吖十的道理™:: The 10 Network ::

Do you post status everyday?

2012-01-29T18:09:00.001+08:00

Some funny comics about Steve Jobs

2011-12-19T14:45:00.001+08:00

Animated Video Wallpaper for JB iphone

2011-09-16T22:52:00.001+08:00

It’s no longer only Android phone enjoys the animated wallpaper & lockscreen on their phone! Now you can have one, if you have a jailbroken iphone.

Start your Cydia, and go to “Manage”.
Then select “Source” and add the following source :
- http://i.danstaface.net/deb/
Upon completion of the source update, search for “vWallpaper2 for iOS4” and install it.
Then, your iphone will be respring by itself and vWallpaper is ready to use on your desktop.

Additional video wallpaper source :

http://cydia.myrepospace.com/PizentuDeWind

The iPhone evolution

2011-09-04T12:33:00.001+08:00

Are you an iPhone fan/supporter?

Source : The iPhone Evolution

How travelers use in-flight WIFI

2011-09-02T00:49:00.001+08:00

Source : How Travelers Use In-Flight WIFI

Top 30 Cydia Tweeks and Apps!

2011-09-01T12:39:00.001+08:00

Nslookup works but ping cannot resolve domain name?!

2011-08-10T21:41:00.001+08:00

Have you experience this? Able to resolve using nslookup but failed to resolve the DNS when perform ICMP ping or traceroute ?

Here’s the solution that you may try, disable the DNS Cache :

> net stop dnscache or

> sc servername stop dnscache

How to completely remove contacts on your iPhone?

2011-07-28T23:16:00.001+08:00

1. Go to “Settings” application on your iPhone.

2. Click on “Mail, Contacts, Calendars” option.

3. Add a new account & select “Microsoft Exchange”

4. Then key in your Gmail username & password. Use “m.google.com” as its Server.

5. Toggle the “Contacts” sync and there will be a prompt to delete all contacts from your iphone.

6. Done.

Play Angry Birds on your PC!

2011-05-17T12:17:00.001+08:00

Now, you no need to have iphone/ipad or android phone to play Angry Bird! All you need is a PC with Google Chrome installed!

Check it out!

Open / Download the free Google Chrome

Download from Google Chrome Web Store and install.

Browse to http://chrome.angrybirds.com and start playing!

The Complete iPhone 5 Rumor Roundup

2011-04-06T10:35:00.001+08:00

Mac Comparisons within 10 years!!!

2011-03-29T00:30:00.000+08:00

OSI Model : Layer 2 (DLC)

2011-03-28T00:13:00.001+08:00

Further to last post on OSI model, let me continue with some information on it. There’re some key parameters that embedded in every layer in one traffic.

Legend :
DA=Destination Address
SA=Source Address
FCS=Frame Check Sequence based on Cyclic Redundancy Check (CRC)
SP=Source Port
DP=Destination Port

Layer 2 frame header Overview

Offset 0-5 and Offset 6-11

At layer 2 (Data Link Control Layer) frame header, source & destination MAC address will be the key parameters ( as shown in the ASCII packet below ). It takes up 6 Bytes for each layer-2 DA & SA and start from offset 0000 in your sniffer’s pcap file.

*( Note : Sniffer will start the capture from Layer-2 DA & SA range, and normally Preamble & 32-bit FCS/CRC will be left )

Offset 12-13

The following 2 Bytes are allocated for the Ethertype, in the example above shows it’s IP type ( 0x0800 ). More info in IEEE Ethertype. This 2 Bytes will indicate the following layer-3 IP header type.

Beside the example here which is Ethernet Version 2 Frame, there’re also some other 802.3 type e.g. IEEE 802.3 LLC Frame, IEEE 802.3 SNAP Frame & Novell Netware 802.3 RAW Frame.

Offset 15-17

If the 2 Bytes following the SA is greater than 05DC HEX ( 1500 Decimal ), the station will identified by Ethernet Version 2. Else, they’re assumed to be a length field. When the following 2 Bytes showing 802.3 length as 38 Decimal ( 26 HEX ) means the following Bytes will be LLC ( Logical Link Control ) header. This sub-layer is acts as an interface between MAC sublayer and the network layer.

Both DSAP ( Destination Source Service Access Point ) & SSAP ( Source Service Access Point ) will be taking up 1 Bytes respectively. This is simply to be the pointer to a memory buffer in the receiving station & of the sending process. Some example will DSAP/SSAP=43, means the following header will be BPDU ( Bridge Protocol Data Unit ).

HEX AA (DEC 170) values are usually employed for the DSAP and SSAP values. Netware uses a HEX 03 in the SNAP Control field and will use the 0x81-37 Ethernet Type value. Usually, the Organizational Code is coded as all 0s (0x00-00-00) and NetWare is no exception.

Offset 17 is simply the Control Byte.

Offset 15-17

The first 3 Bytes i.e. Offset 15-20 is the vendor code. Refers IANA assigned Ethernet-numbers.

Offset 21-22 is the local code, that typically indicate the IEEE Ethertype. This is where the backwards compatibility with Version II Ethernet is implemented.

VLAN ( Optional frame header )

802.1q VLAN tagged frame, is an IEEE standard, uses an additional header in the frames that identifies the VLAN. The 4 Bytes of 802.1q VLAN tag after Layer-2 DA & SA, the Offset 12-15, but it’s optional.

VLAN tag takes up 32 bits in the frame header. The first 16 bits, which located at Offset 12-15 which same with the EtherType/Size field in the untagged frame, is the Tag Protocol Identifier (TPID).

The following 2 Bytes ( 16 bits ) is the Tag Control Identifies (TCI). Priority Code Point( (PCP) the 3-bit field which refers to the IEEE802.1p priority. This indicates the frame priority level, from value DEC 0 (Best Effort) to value DEC 7 (Highest). CFI, or known as Canonical Format Identifier, 1 bit field. CFI normally used to identify between Ethernet ( value 0 ) or Token Ring ( value 1 ).

Another 12-bit field specifying the VLAN to which frame belongs. A value of 0 means that the frame does not belong to any VLAN.

In the case of Q-in-Q ( IEEE802.1ad ), another additional 4 Bytes of VLAN tagging is needed in the frame header. The first 4 Bytes which next to SA will representing the S-TAG ( Service Tag ) and the following 4 Bytes will be representing the C-TAG ( Customer Tag ). IN this case, TPID of the outer S-TAG will be using 0x88A8 to identify it as Q-in-Q packet.

To be continued….

Comparisons : iPad2 & others

2011-03-07T00:43:00.001+08:00

Between iPad & iPad 2 :

Original Post:

iPad 2: Still Ahead of The Competition?
iPad vs iPad 2
iPad 2 vs HP TouchPas vs Motorola Xoom vs BlackBerry PlayBook

Other related post: iPad vs. Xoom vs. iPad 2 Spec Comparison Chart

See how fast Android grow!

2011-03-01T01:06:00.001+08:00

Firefox getting slower and slower?

2011-02-15T01:54:00.001+08:00

Here’re some tips to tune and tweak your Firefox when it getting slower and slower ( or upon installation ) :

Modify the firefox config file

It’s easy to modify, just type “about:config” in your firefox browser, then search for the following parameters and change the value ( just like how you change your registry ) :

network.http.pipelining, set the value from false to true.
network.http.pipelining.maxrequests, change the value from default 4 to a higher value i.e. 8
network.http.proxy.pipelining, set the value from false to true.
browser.sessionstore.interval, change the value from 10000 (10 secs) to 120000 (2 minutes) to increase the firefox backup the session restore point interval.
Add the following parameter ( New->Integer ) and set the value to 0, nglayout.initialpaint.delay.

Securing yourself from a world of hackers

2011-02-09T22:33:00.001+08:00

*Above = Copy Pasted from other’s post.

Also check out my earlier post Good Password Practices

ASCII Table

2011-01-19T12:43:00.001+08:00

Source From : http://www.asciitable.com/

ASCII stands for American Standard Code for Information Interchange. Computers can only understand numbers, so an ASCII code is the numerical representation of a character such as 'a' or '@' or an action of some sort. ASCII was developed a long time ago and now the non-printing characters are rarely used for their original purpose. Below is the ASCII character table and this includes descriptions of the first 32 non-printing characters. ASCII was actually designed for use with teletypes and so the descriptions are somewhat obscure. If someone says they want your CV however in ASCII format, all this means is they want 'plain' text with no formatting such as tabs, bold or underscoring - the raw format that any computer can understand. This is usually so they can easily import the file into their own applications without issues. Notepad.exe creates ASCII text, or in MS Word you can save a file as 'text only'

Slow SSH connection in Ubuntu

2011-01-18T10:49:00.001+08:00

There is always a problem with Ubuntu’s i.e. very slow SSH connection. For some reasons, there’re some options are being enabled by default and causing either the incoming or outgoing SSH connection very slow or hanged in a range from 15 to 60 seconds.

There’re two major contributors which I know of, than can causing the abovementioned problem.

[1] GSSAPIAuthentication

GSSAPI is a ITEF standard for doing strong encrypted authentication in network based applications. OPENssh uses this API and the underlying kerberos 5 code to provide a alternative means of authentication other than ssh_keys.

For some reasons, this feature is enabled by default since Ubuntu Fiesty, you can disable them globally affecting all users in the /etc/ssh/ssh_config

# SendEnv LANG LC_*
# HashKnownHosts yes
# GSSAPIAuthentication yes
# GSSAPIDelegateCredentials no

[2] Slow or Broken DNS Lookup

Everytime when you log into the OpenSSH server, it would actually perform a reverse-lookup on your IP address. If the DNS lookup timed out, then you’ll having big time of delaying as typically OpenSSH will perform 3 times trying.

All you need to do is add the following line in /etc/ssh/ssh_config

sudo echo "UseDNS no" >> /etc/ssh/sshd_config

Remember to restart the ssh services upon change.

How to use full screen mode in Virtual Box for Linux OS?

2010-12-29T22:58:00.001+08:00

First thing, get your Linux OS install in Virtual Box as usual. Am going to use Ubuntu/Debian as example here.

Then, boot up the OS and open the Terminal window :

1. Login using Superuser using

    sudo su

2. Update the aptitude source

    apt-get update

3. Install the packages required :

    a. apt-get install build-essential

    b. apt-get install linux-headers-generic

Once completed, click on the VBox “Devices” menu and “Install Guest Additions”.

Then, go back to the Terminal window :

4. Make a new mount folder,

   mkdir /mnt/vbox

5. Mount the Guest Additions to the newly created folder,

   mount /dev/scd0 /mnt/vbox

6. Install the Guest Additions, depends on either you’re using x86 or 64bit workstation,

cd /mnt/vbox

./VBoxLinuxAdditions-x86.run

./VboxLinuxAdditions-amd64.run

7. Reboot and you shall able use full screen as you like.

Another Cool iPad Apps!!

2010-12-14T01:16:00.001+08:00

iDisplay

Now, you can extend your desktop to your iPad/iPhone!! Just like, you’re extending them to projector, TV etc.

Check this out….it works!

LogMeIn Ignition

This apps, allows you to remote control your desktop, just like well known VNC, teamviewer! Another best part is, they works over NAT from different networks without the needs to configure the proxy, port forwards etc. Now, you can switch on your desktop/laptop and remote control them using your iPad!

Some must have cool iPad apps!

2010-12-12T23:23:00.001+08:00

Here’re some cool iPad apps, that you must have one in your dock…

Weather+ HD for iPad

Flipboard

One of the coolest personal social media that allows you to read news, photos and updates sharing on the Facebook and Twitter. MUST TRY!

Friendly for Facebook

Pulse News Reader

Allow you to read your RSS feeder and link to your Google reader!

土豆网for ipad

How to Disable Autorun 2 for XP

2010-11-14T01:41:00.001+08:00

Last Post : How to Disable Autorun, here’s the updated one.

Create a NoAutorun.reg by adding the following keys using Notepad and execute it to import into your registry:

To disable to AutoRun for all Drives

REGEDIT 4

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
"NoDriveTypeAutoRun”=decimal:255"

To disable & block the execution of Autorun.inf

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\IniFileMapping\Autorun.inf]
@="@SYS:DoesNotExist"

To remove the cache of all mounted drives

[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2]

iBlogger for iPad

2010-11-07T09:54:00.000+08:00

first try with iBlogger...

Limited IPv4 left!!!

2010-11-07T09:37:00.001+08:00

Guess what is it??

2010-08-28T12:15:00.001+08:00

The picture was taken in 1956...

It's a hard disk drive back in 1956... With 5 MB of storage.
In September 1956 IBM launched the 305 RAMAC, the first 'SUPER' computer with a hard disk drive (HDD). The HDD weighed over a ton and stored a 'whopping' 5 MB of data.

Do you appreciate your 8 GB memory stick a little more now?

How to : Quagga Routing Suite

2010-04-25T00:11:00.001+08:00

Quagga, a routing software that run on Linux based on Zebra router, the last Zebra release was 2005. Quagga is able to act as your open-source BGPv4+, OSPFv2, OSPFv3, RIP router installed on Linux system with kernel 2.4 or higher. The best part is you can own a Cisco-IOS look alike router less than RM5K !! Strongly recommend this for your personal study and experimental use.

There’re few daemons that built-up this router :

zebra – routing manager
ospfd - implementing OSPFv2
ripd - implementing RIP v1 and V2
ospf6d - implementing OSPFv3 (IPv6)
ripngd - implementing RIPng (IPv6)
bgpd - implementing BGPv4+ (including address family support for multicast and IPv6)

Download the package from Quagga website, HERE or use Aptitude :

#apt-get install quagga

Here’re some good tips on configuring Debian/Kubuntu based Quagga upon completion of package installation.

To start/stop/restart Quagga service

#/etc/init.d/quagga <start|stop|restart>

To enable/disable the daemons:

#vim /etc/quagga/daemons

zebra=yes
bgpd=no
ospfd=yes
ospf6d=no
ripd=no
ripngd=no

To create configuration files

Firstly, you must create a configuration file, even it is not exist, and each daemons are associated with different configuration files. For example :

zebra – zebra.conf
ospfd – ospfd.conf
bgpd – bgpd.conf

Copy the template or sample configuration files from /usr/share/doc/quagga/examples/.. to /etc/quagga/..

#cp /usr/share/doc/quagga/examples/zebra.conf.sample /etc/quagga/zebra.conf
#cp /usr/share/doc/quagga/examples/ospfd.conf.sample /etc/quagga/ospfd.conf
#cp /usr/share/doc/quagga/examples/bgpd.conf.sample /etc/quagga/bgpd.conf

Add a password to all the newly copied files :

# echo 'password YourPassHere' > /etc/quagga/bgpd.conf
# echo 'password YourPassHere' > /etc/quagga/ospfd.conf
# echo 'password YourPassHere' > /etc/quagga/zebra.conf

You must always ensure the file permissions are correct, it may be vary from your machine/permission settings :

#chown quagga.quaggavty /etc/quagga/*.conf
#chmod 640 /etc/quagga/*.conf

Then, try to restart the Quagga.

debian.conf Configuration Guide

By default, the Quagga daemons are listening to the loopback interface 127.0.0.1 only with different ports for bgpd, ospfd, and zebra respectively, and cannot access remotely. For example, bgpd daemon is using port 2605. Which also means that you can access to the BGP router by executing the following command :

#telnet localhost 2605

If you want to access the Quagga routers remotely from specific IP address, then you may need to modify the /etc/quagga/debian.conf file.

If you want your OSPF router listen to loopback interface and 10.10.10.1, then your configuration will be like :

ospfd_options=" --daemon -A 127.0.0.1 10.10.10.1"

If you wish to let your BGP router to be access from all interfaces IP address, the configuration will be as below :

*For security measurement, I recommend you shouldn’t not allow this.

bgpd_options=” –daemon”

You may need to restart your Quagga services to take effective.

How to configure VTYSH, an integrated shell for Quagga

By instance, if you wish to access to your BGP router :

#telnet localhost 2605

If you found it is not practical or troublesome to telnet into the zebra, ospf and bgp routers separately, you can enable this feature, VTYSH. It has created an interface to access and save the configuration using a single UI, and it looks like your Cisco router!

To use this feature, you need to create the configuration by copy the sample :

#cp /usr/share/doc/quagga/examples/vtysh.conf.sample /etc/quagga/vtysh.conf

Then, edit the configuration /etc/quagga/vtysh.conf and here’s the sample configuration :

!
! Sample
!
! service integrated-vtysh-config
hostname quagga-router
username root nopassword
!

In the sample above, “service integrated-vtysh-config” is remarked and disabled. It would save your configuration separately into the protocol you have updated. Let’s see the example below when OSPF and BGP routers configuration are changed and saved :

#vtysh
quagga-router#write
Configuration saved to /etc/quagga/ospfd.conf
Configuration saved to /etc/quagga/bgpd.conf

If you have enabled “service integrated-vtysh-config” in the config, the configuration will be saved into another file namely, /etc/quagga/quagga.conf. By using this configuration, you will look into quagga.conf first followed by it own protocol files i.e. ospfd.conf when you telnet into it. My recommendation is to disable this feature for easier maintenance and avoid confusion.

#vtysh
quagga-router#write
Configuration saved to /etc/quagga/quagga.conf

Make sure you have enabled “vtysh_enable=yes” settings in the /etc/quagga/debian.conf.

In addition, it’s recommended to add “VTYSH_PAGER=more” in your /etc/environment file, or else you will be annoying by the blinking “END” at the left down corner & requires you to type “q” to continue.

Some of the machine may not works by adding the abovementioned, then you shall need to it in your /home/username/.profile

Ensure the file permission and restart the Quagga service :

#chown quagga.quaggavty /etc/quagga/*.conf
#chmod 640 /etc/quagga/*.conf
#/etc/init.d/quagga restart

Additional Info, IP Forwarding

By default, Linux does not allowed IP forwarding between interfaces. It’s required to enable this by executing the following configurations :

#echo "1" > /proc/sys/net/ipv4/ip_forward

How to change date/time in Ubuntu?

2010-04-20T23:58:00.001+08:00

Linux always have two types of clocks, which are Hardware Clock and System Clock. Hardware Clock, also known as CMOS Clock or Real-time Clock (RTC). System Clock is the software clock used by Linux.

When the system boots up, it would get the time/date from Hardware Clock and set it to System Software Clock. This System Clock may not often accurate, and will experience some clock slipping especially high hardware resources during too many processes running. There’re only two ways to ensure the clock is accurate according NTP, either reboot your system or perform manual synchronization.

To check your current date & time

root:/home# date
Tue Apr 20 07:45:44 PDT 2010

To change the system software clock manually

root:/home# date 042022462010.00
Tue Apr 20 22:46:00 PDT 2010

Format : date <MMDDHHmmYYYY.ss>

To ensure if your system time zone is configured correctly

( Only perform these steps if time/date is NOT CRITICAL on your system, else skip this step )

root:/home# /etc/network/if-up.d /ntpdate
root:/home# date
Tue Apr 20 07:50:41 PDT 2010

It seems like the time zone is not configured properly, change your folder to /usr/share/zoneinfo and select the most appropriate region in the following steps

To change the system time zone

root:/home# ln -sf /usr/share/zoneinfo/Asia/Kuala_Lumpur /etc/localtime

To perform synchronization to NTP using rdate

The time server can be any public NTP server that comply to RFC868

root:/home# /usr/bin/rdate -s time-a.nist.gov

To set your hardware clock time and verify

root:/home# /sbin/hwclock --show
Tue 20 Apr 2010 03:59:03 PM MYT -0.987237 seconds
root:/home# /sbin/hwclock --systohc
root:/home# /sbin/hwclock --show
Tue 20 Apr 2010 10:58:26 PM MYT -0.782410 seconds
root:/home# /etc/network/if-up.d /ntpdate

Refers : Man Page for hwclock

Cesium Atomic Clock, maintain an accuracy of 10⁻⁹ seconds per day!!

Good Password Practices

2010-04-05T00:36:00.001+08:00

The recommendation outlined here are solely based on my current understanding and knowledge, and it is not claimed to be comprehensive or necessary correct.

Password, is a string of secret word or phrase known only to the restricted users or groups that is used for authentication, to prove the identity and to grant the access.

Password policy or password security, is vary from the organization. Many policies require a minimum length of characters, typically of 8 characters and some may also impose a combination of upper and lower case of alphanumeric and special characters i.e. @#$^. Some may also insist on prohibit to use words found from dictionary or user’s personal information e.g. D.O.B. or Identity Card No. (NRIC). The more strict administrator may also prohibits the users to have the same words as the user’s login username or user’s real name.

In addition, there’s some policies may require the users to change their password periodically e.g. 60 days. Based on my own experience, by implementing such a policy may often makes the users unable to remember their password or always create a weaker password as a result that user unable to come up with many passwords or even encourage the users the write down their password! My own recommendation is rather than having a frequent password change policy, the administrator shall insists the users to create a Strong password on the very first place.

According to some unofficial statistics, there’re about 20% of the users are using very simple or “easy-to-guess” password e.g. “password”, date-of-birth, “123456”, “secret”, your city name. last 4-digits of your NRIC etc.

Here’s the password hacking time based on a ordinary user’s workstation :

If the hacker were to use a powerful workstation, it may be faster up to 1000 times!!!

Here’re some good practices :

Always use the strong password.
Do not share or reveal the password to anyone.
Never share a computer account if possible.
Never use the same password for more than one account. Or grouped them in category.
Never write down the password.
Never communicate your password over SMS, telephone, email or even instant messaging.
Always logoff the account and clear the Cache.
Immediately change the password once there is any suspicion that it may have been compromised.
Never use the same password for OS password, application password and account password.
Make sure it is not easy to guess.

What’s strong password ?

At least 8 characters.
Combination of upper and lower case alphanumeric.
Use special character e.g. @#%$^ if possible.
Never use a dictionary word
Never use your special number e.g. date of birth, identity card number etc.
Never use easily guess word based on your personal information e.g. your dog’s name, car number plate etc.
Use a Random Password Generator

Cannot open the Outlook window?!!!

2010-04-03T12:39:00.001+08:00

It shocked me when I first got this message pop-up when I try to start my Microsoft Office Outlook 2007!!! Especially when I have tried several times and even reboot my laptop…it’s still showing the same message….Damm!! I must lost all my emails… Tried to “google” around, and all the resolutions suggested especially from Microsoft support website seem doesn’t really helps…

Reminder: Always backup a copy of all PST files, and running at your own risks!

The solution is very simple, just execute the following command in your “Run..”

“outlook.exe /resetnavpane”

This command is actually just clear and regenerates the Navigation Pane for the current Profile.

Maybank2u on Mobile now!!!

2010-01-22T14:51:00.001+08:00

Starting 19th January 2010, all maybank2u users are able to login using mobile anytime, anywhere using http://mobile.maybank2u.com.my

Here is the main page :

Currently, only four(4) services are offered at M2U mobile which are :

Your account summary
Funds transfer
Make payments &
Check the Forex & Deposit Rates

Example of the account summary :

Logout page….as below : ( And you e71 shall ask you to clear the cache for security purposes )

More info : M2U on mobile

Nokia e71 new firmware released 400.21.013

2010-01-22T00:21:00.001+08:00

Just realized that Nokia e71 had released a new version phone software last month. The latest firmware is 400.21.013 since last updated on March 2009.

Refers Nokia E71 Software Update – v400.21.013 for the change log.

The firmware can be upgraded by using the Nokia Software Updater in your Nokia PC Suite. Always remember to backup your configuration to memory card and fully charged your phone. Find more details from my earlier post.

Refer more details on my earlier posts :
Upgrade your e71 firmware
Nokia e71 new firmware released!

** Try at your own risk **

Life before the computer

2009-12-30T17:01:00.001+08:00

An application was for employment
A program was a TV show
A cursor used profanity
A keyboard was a piano!
Memory was something that you lost with age
A CD was a bank account
And if you had a 3 1/2 inch floppy
You hoped nobody found out!
Compress was something you did to garbage
Not something you did to a file
And if you unzipped anything in public
You'd be in jail for awhile!
Log on was adding wood to a fire
Hard drive was a long trip on the road
A mouse pad was where a mouse lived
And a backup happened to your commode!
Cut - you did with a pocket knife
Paste you did with glue
A web was a spider's home
And a virus was the flu!
I guess I'll stick to my pad and paper
And the memory in my head
I hear nobody's been killed in a computer crash
But when it happens they wish they were dead!

Packet Transmissions : Unicast, Broadcast, Multicast and Anycast

2009-11-29T01:41:00.001+08:00

Unicast, ( refers the left diagram ) is a type of packet transmission sent from a source to another destination. In unicast, there is only one sender and one receiver. Most of the application today is Unicast, example HTTP, SMTP, FTP etc. which employ the TCP transport protocol.

Broadcast transmission, ( refers the diagram below ) is a communication method where a piece of packet/information is sent from a source to all other destinations within the given address range. Broadcasting normally happen on Layer-2 using ARP ( Address Resolution Protocol )

Multicast, ( refers the diagram right below ) is a transmission technology that delivered the sender’s packet or information to a specific groups of recipients. Most common low level protocol to use multicasting addressing is UDP. Unlike broadcast transmission, the recipients only receive the packets if they have previously choose to receive by joining using IGMP. The multicasting is useful when a group of recipients are to receive the same packets from a specific sender over the network at the same time ( refers the diagram below ), it would contribute a significant bandwidth savings and optimizations ( refers the diagram below ). The common usage of the multicasting is IP-television.

Multicast (top) compared with unicast broadcasting (bottom). Orange circles represent endpoints, and green circles represent routing points.

Anycast, ( refers the left diagram ) is another type of transmission that may not commonly discussed. Anycast transmission is mostly used in the routing purposes where the packets are transmits to the destinations via the “best” routing topology. BGP is one of the anycast transmission where the destination IP address/range is received by the source/sender’s router via difference routes but the will be only one route to be chosen for the packet transmission.

**Pictures source from Wikipedia

Chronological of Microsoft Windows

2009-11-28T13:07:00.001+08:00

Microsoft Windows is a series of Operating Systems produced by Microsoft. The first release of Windows was a replacement to the MS-DOS with the enhancement of Graphical User Interface(GUI) on the November 1985 namely Windows 1.0.

I believe most of the reader here has never use it before, I was started with PC-DOS, then followed by MS-DOS6 and ‘jumped’ into Windows 3.0 at about 10-15 years ago. Windows 3.0 was introduced on May 1990 and followed by Windows 3.1 on August 1992 which was much more popular at that time.

On the August 1995, Windows introduced a much more ‘today-look-a-like” windows i.e. Windows 95.

Again, Microsoft created another legend which attracted many users i.e. Windows 98 on June 1998 and Windows 98SE on May 1999. Windows 98SE was actually a much more stable version.

Followed by Windows ME, Windows 2000 Professional and Windows 2000 Server as replacement of Windows NT.

A most popular version of Windows i.e. Windows XP which I am still using it ( never believe any other craps that introduced later i.e. Vista which is too ‘secure’ and troublesome for me ) :P

Read more at Wikipedia : List of Microsoft Windows Versions.

What does DNS registration contact means?

2009-11-01T23:55:00.001+08:00

The Registrant is the licensee of the domain name - this is the individual or company who has the right to use, sell or destroy a domain name.

The Administrative Contact is the licensee's appointed agent for the functions above and any other purpose. In the case that the Registrant is a company the Administrative Contact should be an
employee, director, manager of the company. This person has full authority for all changes in our system so care should be taken in selecting the appropriate person to nominate for this role.

The Technical Contact is the person responsible for maintaining the DNS nameservers associated with the domain name. This enables that contact to make updates if necessary if, for example, the
name of the DNS nameserver changes.

The Billing Contact is the primary point of contact responsible for paying for the domain name's license renewals.

In the case of a company, the company itself would normally be the Registrant. An officer or possibly a trusted employee of the company would be the Administrative Contact.

The Technical Contact would normally be the ISP or webhosting provider (maybe us if you use these services).

In the case of an individual domain name owner, you may be listed as three of the four contacts or conceivably even four of the four contacts. It isn't so important if you're in control of your own domain name but now you can probably see why so many contacts could be required.

How to use Nokia e71 as modem using UMobile data plan?

2009-10-23T01:34:00.001+08:00

Just bought an 018 UMobile Data Plan, cost RM6 with RM5 airtime included. It would be valid for 7 days, and you are required to top up or else the account will be terminated….

UMobile is assigning private IP address to the end user like us and NAT-ed it. Do expect certain applications that required peer-to-peer Public IP address might failed using UMobile. I would also expected some of the TCP/UDP ports might be blocked as well. Will update here once I had verified it. :P

Here’s the steps to configure your Nokia e71 as USB modem to access to the Internet :

1. Firstly, you need to make sure your phone is ready to connect to 3G network. Go to “Menu-->Tools—>Settings—>Phone—>Network” and make sure you select “UMTS” or “Dual-mode” *( By selecting UMTS will makes your connection established/network entry faster )

2. Next, go backward one menu and go “Connection->Access Points” and make sure “U Mobile Internet” profile is configured and ready to use.

3. Connect your e71 to your PC/laptop using USB cable and select “PC Suite” mode.

4. Turn on your Nokia PC Suite and make sure the connection is established. You may see the indication message pop up from your taskbar.

5. Go to “Control Panel—>System—>Hardware—>Device Manager” and make sure your Nokia e71 USB modem driver is detected and properly installed.

6. Go to your “Control Panel-->Network Connections” and create a new connection. Follow the wizard step by step. Select “Connect to the Internet” and click Next.

7. Select “Setup my connection manually” and click Next.

8. Select “Connect using a dial-up modem” and click Next.

9. Put in the meaningful name e.g. UMobile for this connection and click Next.

10. Type “*99#” in the phone number column and click Next.

11. Leave the username and password as <blank> and click Next.

12. Click on the newly created “UMobile” dial up connection. Click “Dial” in the dial up menu as per below :

13. Your Internet connection thru UMobile UMTS network should be ready after the dialup connection.

How to load subtitles in Media Player Classic?

2009-09-13T02:22:00.001+08:00

Make sure you have downloaded the subtitle file ( .sub ) together with your downloaded movie i.e. .avi file. Also make sure that the subtitle file is same filename and located in the same directory with the movie file.

Steps to change the default settings ( which do not load subtitles ) :

1. Launch your Media Player Classic

2. Go to “View”—>”Option”—>”Output”.

3. Change the DirectShow video renderer to either VMR7 or VMR9.

4. Change the both RealMedia Video and QuickTime Video renderers to DirectX9.

5. Done!

p/s: To download the latest version of Media Player Classic ( K-Lite Codec Pack 5.10 Full. Click HERE

The K-Lite Codec Pack is a collection of DirectShow filters, VFW/ACM codecs, and tools. Codecs and DirectShow filters are needed for encoding and decoding audio and video formats.

With the K-Lite Codec Pack you should be able to play all the popular audio and video formats and even several less common formats………….

Alternatively, try VLC Media Player. Click HERE

Print Screen/Screenshot for e71

2009-08-30T21:32:00.001+08:00

Try this application, screenshot, to capture the screen in your e71. It would be useful when you want to print screen and post it online or send to your buddy.

Download the signed version 3.01 from : http://www.antonypranata.com/screenshot/download-screenshot-symbian-os-s60

New QuickOffice is FREE for nokia e-series!!!

2009-08-30T20:34:00.001+08:00

Although it has been offering Free download for nokia E-series, but I believe most of you are yet to upgrade. It is compatible with Microsoft Office 2007 file format i.e. pptx !!!

Steps to download/upgrade to QuickOffice Premier 6

1. Check and verify your current installed version from Menu –> Office –> Quick Office

2. Click on “Options” and select “About application”.

4. Then, select “Updates and Upgrades” and you will able to see the followings menu. Select “Updates and Upgrades”

5. Connect to the network i.e. 3G or Wi-Fi etc. to update the catalogue.

6. Select “Quickoffice Premier 6” from the updated catalogue and download it. You may prompted to provide your email address so that you will receive the order number and download link for your application.

7. Install the downloaded new version of Quick Office Premier 6.

8. Upon completion of the installation, it is recommended to restart the phone.

9. Check on the version again after restart. And now you shall able to see the latest version of Quick Office Premier 6!!!

10. Now, the Quickoffice is ready to use.

Sample email received :

Unable to browse website due to DNS redirection or DNS failure/blocked?

2009-08-23T01:31:00.001+08:00

Suspect some websites has been blocked by your ISP Domain Name Caching Server (CDNS)? There are several steps you should take to solve it.

Steps to query the CDNS :

First, use “nslookup” to query your ISP CDNS. ( Get the CDNS IP addresses by typing “ipconfig/all” )

Go to your command prompt.
Type “nslookup” and Enter.
Then type “server <ISP CDNS IP address>” and Enter.
Type “set q=any” and Enter.
Type the URL domain name that you wish to query.

C:\Documents and Settings\xyz>nslookup
Default Server: DD-WRT
Address: 192.168.2.1

> server 202.188.0.133
Default Server: cns3.tm.net.my
Address: 202.188.0.133

> set q=any
> justk2.com
Server: cns3.tm.net.my
Address: 202.188.0.133

< more…… >

If the URL is blocked, then you will the returned information like below : ( but it may vary from different ISP )

The URL above is blocked and redirect to your localhost i.e. 127.0.0.1.

What should I do if the URL is blocked or redirected ?

There are few different method to resolve this kind of issue. One method is to change your DNS IP settings ( Click here on how to start the OpenDNS )or using proxy server, but you can also create your own DNS resolve list by create a HOST file (only for those blocked websites) in your Windows XP!

Now, try to use other ISP’s CDNS or some free CDNS e.g. 208.67.220.220 and 208.67.222.222 to find out the actual internet IP address (Remember to ignore the MX, nameserver etc. IP addresses) . Use the same method above but changing the server IP address to other CDNS IP i.e. 208.67.220.220.

Steps to change your HOST file :

Locate your host file at C:\WINDOWS\system32\drivers\etc\ for Windows XP. ( For other OS, the host file may stored in different location )
Open the “hosts” file using wordpad or notepad.
If you have never edit this file before or it had never been edited by any other software e.g. firewall software, it should be look like similar as below :

# Copyright (c) 1993-1999 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
#      102.54.94.97     rhino.acme.com          # source server
#       38.25.63.10     x.acme.com              # x client host

127.0.0.1       localhost

4. Append the URL that you have resolved as above at the bottom :

justk2.co.cc 58.121.85.140

5. Then SAVE it.

6. Done!

Additional Tips :

You may also use the same method as abovementioned to block the unwanted URL ( e.g. malware website, parental controlled sites etc. ) by append the target URL to 127.0.0.1. You may add as much as you like!!!

Example :

stupidmalware.com 127.0.0.1

dangerous-site.net 127.0.0.1

For you knowledge :

Wikipedia : Domain Name Server
How DNS Works ?

How to make a scrolling wallpaper on your Desktop

2009-08-23T00:19:00.001+08:00

Steps :

Download a large and long picture. ( Try Daily Wallpaper )
Save it to your Drive C: ( You may change the location as you like )
Click on “Run…”
Type “Notepad” and copy & paste the following codes :

<html>

<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title></title>
</head>

<body bgcolor="#000000" text="#ffffff" leftmargin="0" topmargin="0" scroll="no" style="overflow:hidden">
<table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0"><tr><td valign="middle">
<marquee direction="left" scrollamount="3"><img src="file:///C:/longpicture.jpg"></marquee>
</td></tr></table>
</body>

</html>

5. Change the “C:/longpicture.jpg” to the correct location & file name. Save it to your Drive C: and in .htm format. ( e.g. C:\scrolling.htm )

6. Go back to your Deskop and right-click to “Properties”.

7. Go to “Desktop” tab and click on “Customize Dekstop” as per figure below :

8. Click on the “Web” tab and click on “New”

9. Then you should able to see another newly popup windows. Browse and select the saved .htm i.e. C:\scrolling.htm.

10. Remember to check the newly created Active Desktop as below :

11. Now your scrolling Active Desktop is Done!!!

Tools to backup & restore Mozilla profile and settings

2009-08-02T00:29:00.001+08:00

With this tool, you no longer need to worry to loss your Mozilla i.e. Firefox, Thunderbird, SeaMonkey etc. settings and profiles! You no need to use so many efforts and extensions to backup this and that…

The most important thing is : It is a FREEWARE !!!! Check it out at : http://mozbackup.jasnapaka.com/

Guide to backup & restore Microsoft Outlook 2007

2009-07-31T01:25:00.001+08:00

There is always a headache to backup all your emails, contacts, calendars in Microsoft Outlook or any email client when you change workstation/laptop. Especially for those who have multiple email accounts and multiple .pst data file.

There are ways to backup and restore, let me suggest the method below which I believe it is must easier and secure, and time-saving!

Steps to BACKUP :

Open your old MSOutlook 2007. Go to “Tools”—> “Accounts”. Check the location you stored your email. ( As highlighted in the picture below )

Make sure you copy all the .pst data files into your removable storage i.e. USB HDD etc. Please remind that the .pst files may not store in the same folders depending on your configurations.

Remember the file location ( folder URL i.e. E:\my Outlook\outlook.pst ) as you may need to create the same path in your new laptop.

Go to your Registry Editor, by typing “regedit” in the Runs..

Locate the following item and right-click to export : ( As shown in the picture below ) :

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles\Outlook

Steps to RESTORE :

Copy & paste all the .pst data files you had backup into the same folder URL as per your old laptop ( Step 4 above )
Copy the exported registry file from old laptop and double-click to import the key. ( IMPORTANT NOTE : Make sure there is no existing account being created in the new laptop as this execution may replace all the existing settings )
Open your MSOUTLOOK 2007 and it is ready to use now.

Notes : Please remember your password as these steps above DO NOT backup/keep the password. Try at your own risk !

Nokia e71 upgraded to 300.21.012

2009-07-20T22:17:00.001+08:00

Nokia e71 have a new phone software upgrade again… now they had updated to the latest version 300.21.012 from 210.21.006. But I do not see any major changes in the features yet.

Check your current phone version using “ *#0000# ”

First, launch your Nokia PC suite and upgrade it to version 7.1.30.3 then click on the Phone Upgrade. Always remember to backup all your configuration to memory card!

** Try at your own risk **

How to grab photos from WRETCH ?

2009-06-08T12:28:00.001+08:00

Wretch, is one of the Taiwan famous online album community. There are always people asking on how to download the pictures from this online album ? Rather than using “print screen” then trim it and save it. This online album had disabled the right-click saving feature. After some findings and asking Uncle Google, I found that this program namely WRETCH XD provide a better and easier method to download the photos from Wretch photo albums.

Steps to grab the photo ( After download and execute ) :

1. Double clicked the downloaded .exe file.

2. Put in the account ID as you may found from the Wretch hyperlink and click OK as shown in the picture below.

3. Key in the username & password if the album is protected. Else just leave it blank. Select the albums.

4. Click on the button to start downloading the albums selected as shown below.

Download the Wretch XD software : WretchXD v1.6.0.37

Top 10 misconceptions about Linux

2009-06-01T00:20:00.001+08:00

Today, I found an interesting and very useful article from other’s site Top 10 misconceptions about Linux, please pay a visit and read.

For most computer users, Windows is the only operating system (OS) they’ve ever used. In fact, most people don’t even know about other OSes at all, and that is not good. In our daily lives we always like to have a choice. Whether it’s different flavors of ice-cream or different brands and types of shirts and pants, we like to have a choice. So the question is, why not have a choice with our computers? While we all get to choose whether we want NVIDIA or ATI graphics card, most PCs come with pre-installed Windows operating system. It’s almost shoved down our throats. Where’s the choice in that?

There are many operating systems out there, some are good and some are bad. This list is about Linux, a free open-source operating system. There is a chance you have never heard of it, and even if you have you probably carry a few misconceptions about it. I’ll try to dispel some of these misconceptions starting with the most common:

1. Misconception: Linux is an Operating System (OS)

2. Misconception: Linux is a command line OS

3. Misconception: Linux is for geeks only

and many more….. ( Click here )

How should IT guy write your resume?

2009-03-29T23:38:00.001+08:00

I think it is quite true also, on certains points below, especially when myself studying others’ resume ….hehe

Nokia e71 new firmware released!

2009-03-23T23:41:00.001+08:00

Last week, on the 17th March 2009, Nokia had released another new firmware for Nokia e71. The latest firmware is 210.21.006 since the last upgrade on November 2008 ( refer my earlier blog post : Upgrade your e71 firmware ).

Again, you can check your firmware by typing “ * # 0000 # ”

** Try at your own risk **

Trojan.DNSChanger changed your DNS Settings

2009-03-01T11:50:00.001+08:00

The DNSChanger trojan horse is a small trojan horse application that installed itself in your workstation thru an embedded video codec. It wouldn’t be having ‘big’ harmful to you and the system but it may once in a while affect your Internet online activities.

This trojan is mainly to change your DNS ( Domain Name Server ) in your registry “NameServer” value to a custom IP address e.g. localhost 127.0.0.1 or redirect you to another malicious website. Normally the IP address is encrypted itself in the trojan file, and intend to redirect you to fake website that is looks “alike/same” to the legitimate websites, so that they can steal your private information e.g. banking account access pin/password etc.

Let’s see the search result by MalwareBytes Antimalware in my station :

I found this problem when I am trying update my Live Messenger thru MSN Live updater, it keeps failed. Then I found that the trojan is redirect the msn.com to my localhost 127.0.0.1. The worst part is actually it redirect all the antivirus, antimalwares, anti-trojan or whatever cleaning tool application websites to other IP addresses that causing me unable to download any application! Turnout I have to use another station to download them…

Here are some application that you can download and scan thru your station :

How to disable Autorun?

2009-02-26T22:56:00.001+08:00

Autorun is component feature by Microsoft Windows that dictate the action to execute automatically when the drive i.e. USB drive, CD, DVD etc. is mounted.

Autorun Attack is one of the most dangerous security threat and most listed in anti-malwares statistics.

How to disable ALL type of Autorun through Windows registry ?

Change the DWORD decimal value to 255 :

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoDriveTypeAutoRun]

Create a NoAutorun.reg using Notepad and execute it to import into your registry:

REGEDIT4

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
“NoDriveTypeAutoRun”=decimal:255"

How to disable CDROM Autorun through Windows registry ?

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdrom

Change the DWORD decimal value to “0” :

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdrom\Autorun]

Create a NoCDAutorun.reg using Notepad and execute it to import into your registry:

REGEDIT4

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdrom]
“AutoRun”=decimal:0"

Install Web Server in Nokia e71 ?!!

2009-02-11T22:55:00.001+08:00

Can you believe this? Now you can install web server in your Nokia e71, and it is accessible from Public Network!! Sounds interesting and crazy huh?

This application called Mobile Web Server by My Mobile Sites. It is still the beta versions.

Take a look for the site page that I had installed and browse thru the Internet :

It is accessible using your data connection i.e. GPRS, EDGE, 3G etc. so make you are signing up the correct package before you tried out this application.

The web server will be stopped after you exit from the software.

Don't press #90 or #09

2009-02-09T22:26:00.001+08:00

Receive an email from a friend, do not know if it is true…

Don't press #90 or #09

If you receive a phone call on your mobile from any person, saying that, that they're checking your mobile line, and you have to press # 90 or #09 or any other number.End this call immediately without pressing any numbers.

There is a fraud company using a device that once you press #90 or #09 they can access your 'SIM' card and make calls at your expense.

This information has been confirmed by both Motorola and Nokia.

There are over 3 Million mobile phones being infected by this virus in all around the world now.

Google Location Based Services (LBS) : Latitude

2009-02-09T17:27:00.001+08:00

Just discovered a new application by Google, location-based services (LBS), namely Latitude. With this application, now you can share your location with your friends and buddies! You can even contact them using IM, SMS or voice call.

The interesting part is actually the Nokia e71 or any Symbian S60 devices are supported beside using the PC web-based iGoogle.

What you may see from iGoogle Latitude page as below :

From my Nokia e71 Google Maps Latitude :

To install on your e71, simply browse to http://google.com/latitude and install the latest version of Google Maps.

Upon completion of installation, click on the “Latitude” in the options menu and sign in using your google account.

You can update your location by set it manually or detect by itself using built-in GPS or AGPS compenents. ( Press “0” to look for your current location in Google Maps )

Check it out, it is quite interesting!

Upgrade your e71 firmware

2009-02-08T15:35:00.001+08:00

Finally got my e71 upgraded to the latest firmware! The latest firmware is 200.21.118 ( dated 27-11-2008 ) as shown in the picture below :

You may check your current firmware by using the following key code : * # 0000 #

It is quite simple and really takes time to upgrade, there are few things that you need to make sure before started with the upgrading process, or else you will end up with a software corrupted phone! Then, you will need to send to the shop for “re-installation”!!

1. Make sure your phone is FULLY charged.

2. Make sure you have a fast and reliable Internet connection.

3. Make sure there will not be a power trip that would cause your PC failed, it would be better if you are using a FULLY charged laptop.

4. Good contact USB cable.

5. Turn off the spyware detector, firewall and any other software that would cause the upgrade software to communicate with Nokia server.

6. Make a FULL BACKUP of your phone memory i.e. settings informations, address book, sms etc.

7. Lastly, DON"’T PANIC as instructed by the Nokia Upgrading Wizard…. hehe

First, make sure your Nokia PC suite is the latest version. Check from the About dialog. It should be version 7.1.18.0, else download and upgrade the latest one.

Then, connect your e71 to your workstation. It may need to reboot in other to make sure it works properly, just follow the pop up instructions.

Click on the Upgrade Software icon as shown in the picture above then just follow ALL the instructions. Make sure you really read every single line in the wizard.

Good luck!!

** Try at your own risk **

Shortcut keys for Nokia e71

2009-01-04T13:21:00.001+08:00

General

To get to a symbol or number hold down its key.
Shift + Backspace deletes letters after the cursor.
In icon view:

          A B C D
          E F G H
          I J K L

To open A press 1, 2 for B, 3 for C, * for D, 4 for E, 5 for F, etc.
Fn + Ctrl + C to copy.
Fn + Ctrl + V to paste.
Shift + Left ( or Right ) to select text.
Ctrl + Up for page up.
Ctrl + Down for page down.
Ctrl + Vowels ( or n ) for accented characters like á or ñ.

Camera

T to focus.

Gallery

Green Call to send the image.
Fn + * for full screen.
Fn + 7 to zoom in. Press twice for the full screen size.
Fn + 4 to scroll left while in the zoomed image.
Fn + 5 to zoom in.
Fn + 3 to rotate right.
Fn + 2 to scroll up while in the zoomed image.
Fn + 1 to rotate left.
Fn + 0 to zoom out.
Fn + 2 for full screen video mode.

Home Screen

Hold * to activate/deactivate Bluetooth.
Hold 0 to go to the web browser.
Left Soft Key then Fn ( or * ) locks the keypad.
Hold End/Red to disconnect all data connections.
Hold Left Soft Key to read out new text messages.
To dial 1-800-WHATEVER: type 1800, Fn, Shift twice, type WHATEVER, Call/Green to dial.

Mail

Shift + Return to mark/unmark a single message.
Shift + Down to mark multiple items.
Fn + Spacebar in new message body to access input (predictive text, etc.) options.

Maps

Shift to zoom in.
Backspace to zoom out.
Space to go to the current position.

Music Player

4 for Last Track, press and hold will Rewind.
5 for Play/Pause.
6 for Next Track, press and hold will Fast Forward.
8 for Stop.

Real Player

2 for full screen.
Hold Up for fast forward.
Hold Down for rewind.

Web

1 for bookmarks.
2 to find something on a page.
3 to return to the previous page.
5 to tab open windows.
* to zoom in.
# to zoom out.
8 for page overview.
9 to go to a different web page.
0 to got to the homepage.
Backspace to close the current window.

Factory Hard Reset

Dial *#7370#

============= ** Try at your own risk ** ============

Remote Desktop using your Nokia e71

2009-01-04T13:12:00.001+08:00

Now you can VNC to remote desktop using your nokia e71. There are two(2) applications that I had tried working properly on our Nokia e71 :

1) VNC2GO is a VNC client that runs on MIDP-enabled devices. It lets you control any desktop server running a VNC service, from any mobile device that supports Java Midlets, such as mobile phones and PDAs.

You can download it from ;

Location 1: MIDP1.0 Midlet and JAD Installation File

Location 2: MIDP1.0 Midlet and JAD Installation File

2) VNC Viewer is a native Symbian 9.1 SISX client for Nokia S60 3rd Edition mobile devices (Nseries and ESeries) that allows you to establish a TCP/IP connection to any Windows XP/2003 Server computer running a standard VNC server (from realvnc.com) and control it from the mobile phone.

You can download it from here

How to connect Nokia e71 SIP to Asterisk?

2008-11-26T21:04:00.001+08:00

Today I tried another wonderful feature that built in this Nokia e71, VoIP SIP client. After several testing, it's works! Now, my e71 not only as my mobile phone but also my "mobile office extension phone"! It become an Unified Communication Device with combinations of several features e.g. mobile phone, emails, web browser, extensions phone, instant messenger client etc.

In order to connect your Nokia e71 SIP ( Internet Call ), there are some configurations are needed in your Asterisk Server. You may refers to my sip.conf settings as below :

[1010]
type=friend
secret=1234
qualify=yes
port=5060
pickupgroup=
nat=yes
host=dynamic
dtmfmode=rfc2833
dial=SIP/1010
context=from-internal
canreinvite=no
callerid=device <1010>
call-limit=50

You may also like to configure the "realm" in the sip.conf under [General] context, else you may leave it as default which is "asterisk".

Remember to restart your SIP service to avoid getting Error 400 later in your asterisk debug.

The next step that you need to do is configure your phone ( Make sure there is Internet Connections ).

Step 1:

Go to "Menu"-->"Tools"-->"Settings"-->"Connections"-->"SIP Settings". Then, click on "Options"-->"Add New"

Profile name: <to be defined>
Service profile: IETF
Default access point: <your wifi access point>
Public user name: sip:<SIP user>@<domain or IP address>
Use compression: No
Registration: Always on
Use security: No

[Proxy server]
Proxy server address: sip:<IP address of your asterisk>
Realm: asterisk or <realm of your asterisk>
User name: <SIP user>
Password: <secret>
Allow loose routing: Yes
Transport type: Auto
Port: 5060

[Registrar server]
Registrar server address: sip:<IP address of your asterisk>
Realm: asterisk or <realm of your asterisk>
User name: <SIP user>
Password: <secret>
Transport type: Auto
Port: 5060

Now, you should able to see that your SIP is Registered.

Step 2:

Go to "Menu"-->"Tools"-->"Settings"-->"Connections"-->"internet Telephone Settings". Then, click on "Options"-->"Add New Profile"

Name: <to be defined>
SIP profiles: <previously defined profile>

Try to make an Internet Call by select "Options"-->"Call"-->"Internet Call" after key in the telephone number.

Malaysiakini now on mobile!

2008-11-23T20:03:00.001+08:00

Malaysiakini, is one of the Malaysian online news website. It was first launched on 20th November 1999 and it offers daily news in English, Malays, Chinese and Tamil. Malaysiakini, is one of the independent media which do not have any linkage to political party or commercial interest.

Today, you can browse and read the daily news via your mobile. It could benefit those who riding on the train, LRT or any public transportation to work, they can spend their times more efficiency.

What you need to is just send a SMS with the word "mk" to 32577. Then you shall receive another SMS and just download & install it. It supported on most Java-enabled mobile phone.

Let's see after install in my Nokia e71.

Read this : Read Malaysiakini from your mobile phone

Use your GMail as your Online Storage

2008-11-20T00:10:00.001+08:00

There are several ways that you can use your GMail account as your Online Storage. Gmail Drive is one of the third party software to make your Gmail as storage.

GMail Drive is not supported by Google. It allows a user to access a virtual drive stored in a Gmail e-mail account by causing the contents of the Gmail account to appear as a new network share on the user's workstation.

After you installed the GMail Drive, you will find a GMail Drive in your windows explorer. Right click on this new drive and choose Login As. Enter your Gmail username and password when prompted. It is recommended that you create a new Gmail account for this purpose so that you can keep your existing Gmail account safe. After logging in, you can now copy, paste and create folders in this new Gmail Drive just like any regular Windows folder.

Besides using GMail Drive, you may also use GSpace Firefox extension to access and utilize the GMail account as online storage.

**Try at you own risk ** These applications are yet to "certified" and still under testing.

Online Share : Ovi for Nokia e71

2008-11-18T00:09:00.001+08:00

Ovi, is an application provided by Nokia, and it also an "umbrella concept" by Nokia. It is a personal dashboard to share photos, music just like Yahoo! Flickr photo site. Furthermore, it allows you to sync your contacts, calendars, to-do-list and profile to this online server.

A good news for all Nokia e71 users, it is pre-installed in your device. Check under your "Menu" --> "Media" --> "Share Online".

Remember to create a FREE account in both Ovi.com website and Ovi Share, then you will be able to share your photos online and sync your contacts, calendars etc.

Check it out!

http://www.ovi.com/ ---> Sync your profile

http://share.ovi.com/ ---> Share your photos etc.

Gender Analyzer

2008-11-15T12:35:00.001+08:00

Wow....just came across this website, Gender Analyzer, they claimed that the website is artificially intelligent and able to analyze the website is written by man or woman !! Amazing, have a try on your own website and see if it is true ?!

http://www.genderanalyzer.com/

IPv4 address Exhaustion

2008-11-14T00:00:00.001+08:00

Internet Protocol fourth revision ( IPv4 ) exhaustion referring to the decreasing of the available of the allocations for IPv4. This concern was started since 1980s when the Internet started to grow dramatically. There are many actions being taken to resolve and secure the situation, methods like classful network, C.I.D.R. , D.H.C.P. , network address translations (NAT) and these actions have significantly delayed the exhaustion.

The green grass in the picture below shows the available IPv4 ( but I not sure on the updated, the map was actually created some time ago ) :

Let's see the dramatic growth of the IPv4 usage :

In order to resolve this problem, the experts have introduced the Internet Protocol revision 6 and IPv6 has a much larger address space than IPv4. The IPv6 is built up with 128-bits long and segmented into 8 groups of 4 HEX characters. 50% of it represent the Network ID while the other 50% represent the Network Host.

The experts believe IPv6 will have need a very long time until it is exhausted again! A rough calculation, there are about 350 Trillions Trillions Trillions IP Addresses are available!!! There is someone making the assumption if ONE IPv6 equal to an Atom, then it would takes up more than 1 millions of Empire Tower to represent the entire IPv6 block!! Impressive right?!

A Quote from wikipedia :

IPv6 is intended to be the long-term solution to the IPv4 address shortage. Instead of a 32 bit address, with 4.3 billion possible hosts, IPv6 uses 128 bit addresses, providing 3.4×10³⁸ or 50 octillion for each of the roughly 6.5 billion people on Earth.

Internet Call for Nokia e71

2008-10-27T12:47:00.001+08:00

MediaRing MobileVoIP is another Internet Mobile VoIP Call application Nokia E-series and N-series. Now, you can make VoIP call to mediaring subscriber FREE and lower rate to any non-subscriber.

It offers free mobile to mobile calls regardless of where you and your callers are around the world, and regardless of whether you are with the same mobile service provider or not. If your friend does not have a mobile phone or has not signed up for MediaRing MobileVoIP yet, you can benefit from very attractive low calling rates to anywhere in the world - fixed or mobile phones!

All you need is Nokia E or N series smartphone* and WiFi connectivity to the Internet. Get your family and friends around the world to sign up and you are off to making and receiving mobile calls amongst yourselves absolutely free!

Supported phones :

The below table shows the compatibility firmware for Nokia series :

More info on : http://www.mediaringmobile.com/

Cisco BGP AS Path Regular Expression

2008-10-08T14:21:00.001+08:00

AS path regular expression can be used for displaying BGP routes and AS path access list. AS path regular expression is based on POSIX 1003.2 regular expressions. Following description is just a subset of POSIX regular expression. User can use full POSIX regular expression. Adding to that special character '_' is added for AS path regular expression.

IM using your mobile

2008-10-04T19:28:00.001+08:00

IM, so called Instant Messenger, i.e. MSN, Yahoo! Messenger, Skype, Google Talk etc. is a tool that transform real time communication on text-based form between two(2) or more individual over the IP data network. It has become an important communication tool in our daily life.

Todays mobile phone has been embedded with various form of data communication transport methods like GPRS, GSM 3G, HSPDA, and the most cost saving method --> 802.11b/g WiFi. And I believe the mobile phone which built in with the 802.16e WiMAX chipset will be on the market very soon.

Thus, it also means that you can have your Internet data communication ON with you wherever you are, and full mobility! The most important thing is that with the WiFi network meshed around the cities in the world and WiMAX network which start growing everywhere in the world! And it is FREE or should I call it unlimited usage on a fixed charges.

Today, Windows Live has ready with Messenger Mobile client - Windows Live Goes Mobile. You can chit chat via mobile, check your hotmail, even MSN "spacing". Check it out... http://www.messengergoesmobile.com/

I prefer another application called Fring. The greatest thing for Fring is it built in many messenger clients like MSN, Skype, Google Talk, ICQ etc and the greatest client is the SIP client. With this, now I can have my office extension number following me whenever I am, and it is a mobile extension phone!

How Fring work?

Check out more from Fring's website.

Let's see and now my Nokia e71 is equipped with Fring also!! haha...

Hard reset (Default) on your Nokia e71

2008-09-28T01:43:00.001+08:00

There will a time, you will find that your phone works slower and slower...or even hang!! Before you bring it to the center or technician to re-format it, you can maybe save your money and try perform a hard reset ( default/factory reset ).

Please always remind to backup your configurations and data FIRST! You can find the backup function in the Nokia Phone Suite application. Also remember to sync your address book either to Micosoft Outlook, OE or any raw data format. For SMS/MMS backup, you can change the storage location from phone memory to your external memory card.

To change the SMS/MMS storage location :

Go to "Menu"-->"Communication"--->"Message"
Click on "Options"-->"Settings".
Select "Other"
Change the options for "Memory in use" to "Memory card".

To hard reset :

Click " * # 7 3 7 0 # ".
Then it will request for your Lock Code, use "12345" unless you had previously changed it.

Everything will be back to the factory settings. What you need to do now is reinstall your applications, sync back the address book and restore the configuration data.

Display a cool clock on your e71

2008-09-20T21:32:00.001+08:00

Just notice this a couple days ago, now you can use your Nokia e71 as your clock without pressing any buttons! And it is cool...I think! :P

Before enable this symbian clock, you need to press the center button to display the clock ( see the photo below ) :

Now, you can have something like this ( see the photo below ) on standby mode :

So, what you need to do is just go the any specific profile that you are using. Then "turn Off" the breathing light.

Free WiFi in Penang : Wireless@PENANG

2008-09-19T19:40:00.001+08:00

Further to the Wireless@KL which I personally had an bad experience on it, never able success to get online thru it or even browse to it portal page! ( Just keep showing "under maintenance" ) It happen in most of the wireless@KL in the heart of the Kuala Lumpur!

Back to the topic, on this day 19th Sept 2008, Wireless@PENANG is launched by the Chief Minister Lim Guan Eng. Penangites is going to enjoy free wifi wireless network within Penang! Their target to complete it within 18 to 24 months.

It sounds great, isn't it? You can now login to your messenger tool like MSN, Yahoo! all day long using Wifi instead of expensive and unstable crap 2G or 3G network! You can even make voice call to your buddy using skype and it is all Free! Cool!

Again, back to the realistic. How stable and how brilliant the network maintenance will be ? How the team would handle the 2.4GHz RF interferences and hand-over ? It would some of the challenges ( there are actually more.. ) that the operator and the network builder have to iron it...

References :

The Edge Daily : Penangites to enjoy free WiFi services

The Star : Penang launches statewide free WiFi project

How to send messages within a shell terminal in Linux ?

2008-09-15T02:38:00.000+08:00

There are TWO(2) common methods that you can communicate and send messages between users in shell terminal in Linux. Most of the kernel is compiled with the package, i.e. wall and write.

Wall is a command to send message to everyone in the shell terminal, in the other word means broadcast the message.

( Refer Wall Manpage )

Example :

root@localhost:/# wall ( press Enter )
Hello Testing...broadcast using wall ( Ctrl-D to broadcast )

Broadcast Message from josephlee@localhost
(/dev/pts/2) at 22:21 ...

Hello Testing...broadcast using wall
root@localhost:/#

Write is a command to send message to a specify user in the shell terminal. Normally you will also need "who" or "w" command to find out who is in the terminal.

( Refer Write Manpage )

Example :

root@localhost:/# write testuser ( press Enter )
Testing 123... ( Ctrl-D to send )

Message from josephlee@localhost on pts/2 at 22:26 ...
Testing 123...
EOF
root@localhost:/#

How to get WLAN MAC Address in Nokia e71 ?

2008-09-14T01:32:00.001+08:00

There might one day you want to find your Nokia e71's wireless MAC address for whatever purpose e.g. configure a static fixed lease in your DHCP server, monitor the bandwidth usage etc. Or it may also useful when you are trying to 'hook' it to another wireless device which only able to configure and it is filtered by MAC address.

So, this is way on how you can get your WLAN MAC address :

Press " *#62209526 "

Definition for MAC Address for those who don't know what it is...a definition from Wikipedia :

In computer networking, a Media Access Control address (MAC address) or Ethernet Hardware Address (EHA), hardware address, adapter address or physical address is a quasi-unique identifier assigned to most network adapters or network interface cards (NICs) by the manufacturer for identification. If assigned by the manufacturer, a MAC address usually encodes the manufacturer's registered identification number..... ( more here... )

I got my Nokia e71!!

2008-09-10T20:43:00.001+08:00

This is my new phone, Nokia e71 !!

Wowow....just got it couple of weeks ago. Initially I was waiting for the WiMAX 802.16e ready handset, then I had made up my mind --->> "Don't wait anymore, it still need some times for WiMAX ready handset, especially those smart phone, to be in the market~"

Until Today, I strongly recommend for this phone, kudos Nokia!!Today onwards, I will post some info, useful applications and my experience on this phone beside posting the Networking & Linux related article.

My Nokia's phone software version :
( You may check yours by pressing the Mobile Secret Code *#0000# )

100.07.76 <--- Software version
08-06-2008 <--- Software release date
RM-346 <--- Compression Type
(C) Nokia E71-1 (26)

More specifications info from Malaysia Nokia Web

How to prevent MSN Messenger SPAM

2008-09-08T00:12:00.001+08:00

Recently got lots of MSN messenger spamming...really irritating, sigh~ Look at the photos below for some example :

If you are using Windows Messenger :

Click 'Start' and then 'Control Panel' .
Click 'Administrative Tools'.
Click 'Services'
Locate 'Messenger', right-click select on your mouse and select 'Properties'
Under 'General' tab / 'Startup Type' select 'disabled' from the drop down menu
Click The 'Stop' button
Click 'OK' to save

If you are using MSN Messenger :

Click ‘MSN Messenger Service’..
Click ‘Tools’, and select ‘Options’.
In ‘Options’ dialog box, click ‘Privacy’ and select ‘Alert me when other users add me to their contact lists’.
When someone tries to add you to their buddy list, a dialog box will ask if you want to allow him or her to contact you. If this request is from a stranger or someone you don't want to hear from, check 'Block this person from seeing when you are online and contacting you.'

If you still encounter the same problem after performing the steps above, try the steps below :

Click ‘Messenger Service’.
Click ‘Tools’, and select ‘Options’
In the ‘Options’ dialog box, click ‘Privacy’, and select ‘All other users’ and click ‘Block’. This will prevent people who are not on your buddy list from sending you messages or adding you to their contact lists.

Note: New friends will also be prevented from adding you to their contact lists unless you add them to your list first.

Google is announcing it browser Chrome!

2008-09-03T00:39:00.001+08:00

Rumours of a Google browser project since year 2004, now a posting in Google official blog has makes it much more tangible.

Google has stated that Chrome will be an open source application, with the terms described indicating a BSD or Apache permissive licence. A beta version for Windows will be released on September 2nd with Mac and Linux versions being developed. The company is hosting a press conference at its Mountain View, Calif., headquarters Tuesday at 11 a.m. PDT.

The comic book is now available on Google Books. It gives a "human-readable" or rather we called it "layman-readable" format for it technical details on this Google Chrome project.

IEEE 802.11r WiFi roaming standard approved!

2008-08-31T03:16:00.001+08:00

The newest Wi-Fi protocol, 802.11r, which has become the de facto "Wireless VoIP standard", is now a published standard of the Institute of Electrical and Electronics Engineers (IEEE) standards board.

On this day, 29th August 2008, the IEEE has formally announced that 802.11r is approved. According to Wikipedia, IEEE 802.11r-2008 or fast BSS transition (FT) is an amendment to the IEEE 802.11 standard to permit continuous connectivity aboard wireless devices in motion, with fast and secure handoffs from one base station to another managed in a seamless manner.

The arrival of 11r is timely. Voice over Wi-Fi is expected to generate increased interest as more dual-mode Wi-Fi/cellular solutions are delivered this year. 802.11f provides a fast enough hand-off for data services, but that can take a second or two if cryptography is being used, so 802.11r was kicked off in 2004 to provide consistent connections. The handoffs take place in less than 50 milliseconds, rather than the several seconds needed to negotiate a secured connection.

Given the need to integrate with 802.11i security and 802.11e QoS standards, developing a workable standard for fast roaming is challenging. Not surprisingly, 11r defines a complex architecture, though one that is not expected to require forklift upgrades of existing hardware. But getting all the software right will be difficult.

Mobile Number Portability in Malaysia

2008-08-29T02:01:00.001+08:00

After YEARS of discussing this topic, MNP, by the MCMC. Finally, it will be implemented on 29th August 2008 ( Friday ). It would started for Pre-paid user and followed up by Post-paid user in a couple of weeks. The nationwide launch for the MNP service is in October.

With the MNP implementation, the mobile user no longer 'tight' with their mobile service operator. You will have the convenient freedom of switching to competing mobile service operators while retaining your respective phone numbers. It means that you can switch any operator from Digi to Maxis or Maxis to Celcom etc. with your phone number e.g. +6016-XXXYYYY remains the same!

There will be a RM25 charge everytime the MNP is used to switch to a new operators.

More info on MNP : http://en.wikipedia.org/wiki/Mobile_number_portability

Windows 7 launch in 2009 ?

2008-08-24T13:40:00.001+08:00

Take it as a sign that Windows Vista is a failure to the market ( Even I am downgrading from Vista License to XP for my new Dell laptop ), rumors claims that the Windows 7 might be release earlier in early 2009?!

Windows 7, formerly codenamed as Blackcomb or Vienna, is the working code name by Microsoft as a successor of Windows Vista. Microsoft spokemen claims that Windows 7 will be focusing on user centric, performance improvements and break the compatibility issue with Vista that Vista has with previous version.

More info on : Windows 7 News

Some screenshots for Windows 7, it is fake or real ?

More screenshots:

Feast Your Eyes on the Leaked Screenshots of Windows 7 M1 Ultimate Edition!

Windows 7 screenshots are they true?????

How to perform DNS query from your command prompt

2008-07-27T17:52:00.001+08:00

If you are familiar with Linux network administrative, you will find that it will be more troublesome when you switched over to Windows based administration...I believe some of you who have the same experience will agree with me. :P

Now we can also perform DNS query ( e.g. dig, whois etc. ) from Windows command prompt, instead of browse to online webpage or SSH into the Linux server.

How to install the DNS query tool

Download the package from here or here and unzip it to C:\dig.
Edit the resolv.conf and replace the nameserver to your DNS server.
Save and copy the resolv.conf to C:\Windows\System32\drivers\etc
Go back to C:\dig, right click the doshere.inf and select Install.
Edit the Environment Variables ( can be found under [Control Panel]-->[System]-->[Advanced] )
Edit the "Path" and append "C:\dig" at the end of the line.
Now, you should be able to use the DNS query from command prompt!

Example on DNS query :

Show the name servers that controlling .my domains
- dig my. NS
Show the name servers that controlling justk2.com
- dig justk2.com NS
Show the Mail Exchange for justk2.com
- dig justk2.com MX
Show the IP address for the web, 10network.justk2.com
- dig 10network.justk2.com
Show the hostname of the IP address
- dig -x 203.158.28.18
Show whois is owning the justk2.com domain
- whois justk2.com

More informations at : Dig Manual Page

Use your Windows as Router

2008-07-27T00:26:00.001+08:00

Do not have money to buy router? or your router is spoilt and cannot work properly??!! Now, you can use your Windows as a router easily.

Enable the IP Forwarding in Windows XP

Go to registry editor. Click on "Start" --> "Run..", type "regedit" and press ENTER.
Then go to [HKEY_LOCAL_MACHINE]->[SYSTEM]->[CurrentControlSet]->[Services]->[Tcpip]->[Parameters]
Modify the [IPEnableRouter] value from "0" to "1".
Then, reboot your Windows.

Download the 3rd Party Software : NAT32

This is one of easier software to use and configure as NAT server. Download from NAT32 Windows Software Router.

Before you install the Setup.exe, you may need to install the Protocol at your network adaptor.

Go to your network adaptor properties page.
Then click "Install" and select "Protocol" then "Add"
Click the "Have Disk" and specify the directory into which you unzipped NAT32.
Select the required .inf file ( use NDIS3P2K.inf for XP )
Click OK.
Reboot your Windows to start the driver.

How to resolve visitor's IP address using PHP?

2008-07-23T23:46:00.001+08:00

Recently working on some PHP programming to resolve the visitor's IP address when visiting to my PHP page :

<html>
<head>
<title>What is my IP address</title> </head>
<body>
<?
    if (getenv(HTTP_X_FORWARDED_FOR)) {
        $pipaddress = getenv(HTTP_X_FORWARDED_FOR);
        $ipaddress = getenv(REMOTE_ADDR);
echo "Your Proxy IP address is : ".$pipaddress. " (via $ipaddress) " ;
    } else {
        $ipaddress = getenv(REMOTE_ADDR);
        echo "Your IP address is : $ipaddress";
    }
?>
</body>
</html>

Build your own Network Attached Storage(NAS)

2008-07-21T00:27:00.001+08:00

Need a network attached storage (NAS) ? Feel expensive to get one from the store ? Now, you can make your own with a normal desktop PC !!! Want to know about NAS ? Click here

Before you get started, make sure your hardware requirements as :

Minimum of 96MBytes of RAM.
A bootable CD Room.
or you may also install it in a virtual drive.

FreeNAS, is a open source FREE network attached storage running on FreeBSD 6.2 distribution and it is web-based GUI. I had just installed one FreeNAS on a server, and comparing it to Buffalo NAS, it is more powerful and more features!!!

FreeNAS, not only able to provide you the storage access using NFS and FTP, you may also use it a rsync server! Besides, it do support Samba (SMB) used by Microsoft Windows Network FIle System.

FreeNAS is probably one of the easiest installations out there. I can’t believe that it takes only a few minutes to perform a complete installation of an operating system.

FreeNAS can be downloaded from it website or through the FreeNAS SourgeForge Site. Choose the latest image (ISO) and get it downloaded. It would takes you some times if you are using a low bandwidth Internet access.. :) Burn the image into a CD and start your installations.

Simple guide to install FreeNAS :

Boot up the burned ISO CD until you reach the console text-based installation menu as below :
"Console setup"
"*********************"
1) Assign Interface
2) Set LAN IP address
3) Reset WebGUI password
4) Reset to factory defaults
5) Ping host
6) Shell
7) Reboot system
8) PowerOff system
9) Install to a hard drive/memory drive/USB Pen, etc
First, assign the interface by clicking "1" then followed by setting the IP address, option "2".
Then, you may proceed on the installation by clicking option "9". ( This option will be disappeared if you had installed successfully into the hard drive. )
"Install"
"*********************"
1) Install on HD, CF or USB key: Create 1 UFS partition
2) Install on HD: Create 2 UFS partitions (OS and DATA)
3) Upgrade existing installed version from CDROM
4) Return to main menu
You can select either install the FreeNAS boot partition and data partition on the same partition or you can seperate it for both boot partition and data partition. It is recommended to select option "2" here so that you can use the remaining space in the HDD as Data storage.
Once the FreeNAS is install completed, remove the CD.
Then select "4" to exit to the main menu, and select "7" to reboot the system.
Now, you may access the Web interface by browsing to the http://<IP_ADDRESS_CONFIGURED>.
The default username : admin and password : freenas
Download the manual here, or browse to the online manual. Proceed with the configurations.
Then, you NAS will be ready to use! Good luck ya...

GOOD extensions for Firefox 3

2008-06-29T03:06:00.001+08:00

Have been migrating my favourite browser Mozilla Firefox from version to 2 to version 3 weeks ago. It seem to be more features and 'upgrades' from the earlier version but the most headache thing is that many of the extensions I used is not compatible with this version yet!

In order to optimize the usage of this version, I had found some good extensions that can be used with Firefox 3.0.

1. Googlepedia

Shows you a relevant Wikipedia article along with your search results. Clicking links in the article will trigger new Google searches, making it a very useful research tool...

This is a good extensions for those who always seek for Uncle Google on their research especially thru Wikipedia.

2. FoxMark Bookmark Synchronizer

If you use Firefox on more than one computer, you'll want Foxmarks. Install Foxmarks on each computer, and it will work silently in the background to keep your bookmarks synchronized. You can also log in to my.foxmarks.com to manage your bookmarks from any computer.

3. FireFTP

FireFTP is a free, secure, cross-platform FTP client for Mozilla Firefox which provides easy and intuitive access to FTP servers.

4. IE Tab

IE Tab is an extension for the Mozilla Firefox, Flock and SeaMonkey web browsers. IE Tab allows users to view pages using the Internet Explorer rendering engine from within Firefox. This may be useful for viewing pages that only work in Internet Explorer (e.g. Windows Update) without exiting Firefox. Pages viewed through the IE Tab extension will be recorded in Internet Explorer's history, cache, and so on, as if they had been viewed directly in Internet Explorer. It appears to function by calling the installed version of Internet Explorer on the user's computer, and then running the output within a tab in Firefox.

5. Scrapbook

ScrapBook is a Firefox extension, which helps you to save Web pages and manage the collection. Key features are lightness, speed, accuracy and multi-language support. Major features are: Save Web page, save snippet of Web page, save Web site (In-depth Capture) etc.

6. MeasureIt

Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.

7. GSpace

Gmail gives you nearly 7 GB of free storage. With Gspace, you can turn some or all of that into free online storage of files that you can access from anywhere.

8. FlagFox

See a flag in the status bar that tells you what country the server is in for the website you are on. You can then look up more detailed information on the server, giving you some extra security in case the site is a fake

9. Broadband Speed Test and Diagnosis

This extension includes a set of tools for broadband users. It can measure the bandwidth of Internet connections and perform diagnostic tests (connectivity, ping and traceroute etc).

10. Facebook Toolbar

The Facebook Toolbar for Firefox is a free extension for Firefox that lets you extend your Facebook experience into your everyday browsing.

11. Google Preview

Inserts preview images (thumbnails) of web sites into the Google and Yahoo search results pages.

12. Webmail Notifier

Get notifications of new email in your status bar for services such as Hotmail, Gmail, Yahoo Mail and more.

13. Reload Every

The Reload Every extension adds an option to the context menu (the menu you obtain by right clicking on the web page you're currently viewing) to reload the web page you are viewing every so many seconds or minutes. You can also access reload every by using the dropdown menu next to the reload button on the toolbar This can be handy if you have a page with for example sports scores, news or stock quotes and want to refresh them automatically.

14. Color Zilla

An extremely handy tool for Web developers to let them see the RGB and Hex values of any color on a Web page.

15. PDF Download

PDF Download relieves the pain experienced when encountering PDF files on the Web. Whenever you click on a PDF file, PDF Download lets you know before trying to open it, and then offers you choices such as downloading, opening, or converting it straight to HTML.

16. Meebo

Instant messaging across all major IM networks like MSN, Yahoo!, Goole Talk etc. built right into Firefox.

"nslookup" Command

2008-06-27T22:56:00.001+08:00

The nslookup command can be used in Windows and Unix-based to find various information related to DNS ( Domain Name Server ) including the IP addresses, MX records for a domain or the NS Servers of a domain.

1. To look up the reverse for an IP address :

C:\>nslookup
Default Server: cns3.tm.net.my
Address: 202.188.0.133

> set q=a
> 203.158.28.18
Server: cns3.tm.net.my
Address: 202.188.0.133

Name: cdns1.bizsurf.net
Address: 203.158.28.18

>

2. To make query using another server :

> server 202.188.1.5
Default Server: [202.188.1.5]
Address: 202.188.1.5

> www.justk2.com
Server: [202.188.1.5]
Address: 202.188.1.5

Non-authoritative answer:
Name: justk2.com
Address: 202.75.41.193
Aliases: www.justk2.com

>

3. To look up the forward for a Fully Qualified Domain Name (FQDN) address :

> set q=a

> www.justk2.com
Server: cns3.tm.net.my
Address: 202.188.0.133

Non-authoritative answer:
Name: justk2.com
Address: 202.75.41.193
Aliases: www.justk2.com

>

4. To look up the Server of Authority (SOA) record :

> set q=soa
> justk2.com
Server: cns3.tm.net.my
Address: 202.188.0.133

Non-authoritative answer:
justk2.com
        primary name server = ns1.everydns.net
        responsible mail addr = hostmaster.justk2.com
        serial = 1214570007
        refresh = 3600 (1 hour)
        retry   = 900 (15 mins)
        expire = 1209600 (14 days)
        default TTL = 3600 (1 hour)
>

5. To look up the Mail Exchanger (MX) record :

> set q=mx
> justk2.com
Server: cns3.tm.net.my
Address: 202.188.0.133

Non-authoritative answer:
justk2.com      MX preference = 5, mail exchanger = mail.justk2.com
justk2.com      MX preference = 50, mail exchanger = bkpmail.localdns.com

bkpmail.localdns.com    internet address = 202.75.41.58
mail.justk2.com internet address = 202.190.203.180
>

6. To look up all records for a particular FQDN address :

> set q=any
> justk2.com
Server: cns3.tm.net.my
Address: 202.188.0.133

Non-authoritative answer:
justk2.com
        primary name server = ns1.everydns.net
        responsible mail addr = hostmaster.justk2.com
        serial = 1214570007
        refresh = 3600 (1 hour)
        retry   = 900 (15 mins)
        expire = 1209600 (14 days)
        default TTL = 3600 (1 hour)
>

7. To look up what name server handles the reverse for a particular class network ( i.e. 202.75.41.* ) :

> set q=any
> 41.75.202.in-addr.arpa
Server: cns3.tm.net.my
Address: 202.188.0.133

Non-authoritative answer:
41.75.202.in-addr.arpa nameserver = ns02.myloca.com
41.75.202.in-addr.arpa nameserver = ns01.myloca.com

41.75.202.in-addr.arpa nameserver = ns02.myloca.com
41.75.202.in-addr.arpa nameserver = ns01.myloca.com
ns02.myloca.com internet address = 202.75.34.2
ns01.myloca.com internet address = 202.75.34.1
>

The Father of Spam

2008-06-14T23:57:00.001+08:00

Do you know the guy below ? Probably almost all of us ( or should I says none of us ) know who he is? But he had be an important people in IT networking world.

Gary Thuerk, he was the FIRST SPAMMER in the world. On the 3rd May 1978, he sent out the first spam over the network of government and university computers known as the ARPAnet. A marketing manager for Digital Equipment Corp., he wanted to publicize open houses in Los Angeles and San Mateo where the company's latest computers would be unveiled. There are several thousands of scientists in ARPAnet and he want to invite all of them!

Network Attached Storage

2008-06-02T00:08:00.003+08:00

Network Attached Storage, also known as NAS, is a file-level computer data storage that connected to a network and providing data access to data clients.

The NAS is solely a computer that connected to a network with own installed stripped down and minimal operating system. The unit is oftenly not and unable to carry out other functionalities as other computer may have. NAS unit normally do not have keyboard+mouse and display, it is controlled and managed over network by using web-based browsing.

NAS uses file-based protocol i.e. NFS ( Sun Network File System ) on linux system or SMB ( Server Message Block ) on windows-based system. NAS units rarely limit clients to a single protocol.

More info on NAS : http://compnetworking.about.com/od/itinformationtechnology/l/aa070101a.htm

The benefit of using NAS

Availability of data might potentially be increased with NAS if it provides built-in RAID and clustering.

Performance can be increased by NAS because the file serving is done by the NAS and not done by a server responsible for also doing other processing. The performance of NAS devices, though, depends heavily on the speed of and traffic on the network and on the amount of cache memory (RAM) on the NAS computers or devices.

Buffalo

The Buffalo network-attached storage series are network-attached storage devices sold around the world, for example by US, European and Japanese computer retailers, and have been reviewed by the computer press. They can be modified into miniature general purpose Linux-based computers. The LinkStation and TeraStation are intended for the general public, while the Kuro Box is intended for expert hackers as a cheap platform for Linux development.

<-- Click me

One of it famous product is Buffalo TeraStation.

List of NAS manufacturers

My experience on Buffalo....

"I used this product once for my office, the system was CRASHED and the RAID system was failed. Suppose by using RAID5, it should be able to recover the lost data from the redundant hard disk but the worst thing was the data inside was TOTALLY LOST and the support told me, it is unable to recover....damm!"

Ever since that, I have lost my confidence on this product and the support as well.

Just found out an open source NAS system...think gonna get a computer and try it on. Be back on the configuration steps and the experience once I had tried it....

[Update: 21st July] Click here, to find out more on how to build your own Network Attached Storage

Build you own SIP server : Asterisk

2008-06-01T02:35:00.001+08:00

With these applications, you can configure your own IP PBX easily at office, or even at your own house! It is easier than you think~

Trixbox

It has FREEWARE! Now you no need to know and crack your head to figure out how to look into MANY MANY config files in linux...it is all GUI, for standard feature if you are looking for.

http://www.trixbox.org

AsteriskNOW

This is another open source freeware that just came across, an open source that built up with customized linux distributions that includes Asterisk! AsteriskNOW is much more easier than Trixbox, you can create your own voice sip server within a day! Easy to install, and offer flexibility, functionality...but it is not advanced type. If you are looking for some 'great' features, then it is not suitable for you.

http://www.asterisknow.org

If you are looking for Analog FXO/FXS Gateway ( What is FXO & FXS ? ), maybe you can try Digium or Planet for home user. Definately, you may go for Cisco as well...

What is FXO and FXS ?

2008-05-26T23:49:00.001+08:00

FXO and FXS are the ports used by the analog phone or known as POTS ( Plain Old Telephone Service )

FXS, known as Foreign Exchange Subscriber interface, is the port which actually provide analog line to the subscriber. It is the "socket on the wall" which delivers a dialtone, battery current and ring voltage.

FXO, known as Foreign Exchange Office interface, that deliver the analog line. It is the port on your analog telephone/fax machine incoming port. It delivers an on-hook/off-hook indication (loop closure).

How does it works, technically ?

The FXO and FXS is always working on a pair. A FXO port is always connected to a FXS port or vice versa.

Technically, when you wish to make an outbound call :

You pick up the phone from FXO devices. Then FXS port will detect that it is OFF-HOOK.
When you dial a number, a DTMF ( Dual-Tone-Multi-Frequency ) digits will be passed to FXS port.

When there is an inbound call :

When FXS received an incoming call, it will generate a DC ring voltage to the FXO device.
The FXO device ( phone ) will rings.
You pick up the phone, and line is established.

Note: The analog phone line passes approximately 50 volts DC power to the FXS port. That’s why you get a faint ‘shock’ when you touch a connected phone line. This allows a call to be made in the event of a power cut.

Type of connections

Without PBX system ( i.e. home land line )

A phone is connected directly to the FXS port ( on the wall jack ) which provided by your landline company.

With PBX system

If you have a PBX, then you connect the lines provided by the landline company to the PBX and then the phones to the PBX. Therefore, the PBX must have both FXO ports (to connect to the FXS ports provided by the telephone company) and FXS ports (to connect the phone or fax devices to).

With FXO Gateway

To connect analog phone lines to an IP phone system, you need an FXO gateway. This allows you to connect the FXS port to the FXO port of the gateway, which then translates the analog phone line to a VOIP call.

With FXS Gateway

An FXS gateway is used to connect one or more lines of a traditional PBX to a VOIP phone system or provider. You need an FXS gateway because you want to connect the FXO ports (which normally are connected to the telephone company) to the Internet or a VOIP system.

With ATA adaptor ( FXS adaptor )

An FXS adapter is used to connect an analog phone or fax machine to a VOIP phone system or to a VOIP provider. You need this because you need to connect the FXO port of the phone/fax machine to the adapter.

Source from 3CX

AAA Server and Concept

2008-05-25T18:40:00.001+08:00

AAA server , is known as Authentications, Authorizations and Accouting Server, and it used for access control. Authentication identifies the user. Authorization implements policies that determine which resources and services a valid user may access. Accounting keeps track of time and data resources used for billing and analysis.

Authentication

This is kind of process to establish a digital identity between entities which refering to a client and a server. The authentication is done via presenting an identity ( i.e. login user name ) and a credentials ( i.e. password, digital certificates, one-time-token etc. )

Authorization

This is a process for granting privileges ( or blocking ) to a client by server after authentication process, what privilege requested and the current system state. The authorization is based on :

Time-of-day restriction.
Physical location restriction.
Restrictions again multiple login at a single point of time.
Ability to gain access to certain service :

IP address and TCP/IP settings.
Routing information
QoS
Bandwidth allocated.
Encryptions and tunnelling
and so on.

Accounting

This process is to collect the consumption information of an user for network management, planning, billing purposes etc. There are some typical information that being gathered are the identity of the user, the nature of the service delivered and the period that the service being used.

Type of AAA Protocol

There are few common types of AAA protocol, which are :

Radius
DIAMETER
TACACS
TACACS+

Some combinations with the protocol and AAA protocol above are being used :

PPP
EAP
PEAP
LDAP etc.

Refers : The webpage of the Authentication, Authorization and Accounting IETF working group

I will continue in Radius and Diameter AAA protocol in the following posts, remember to come back ya...~

What is DHCP server?

2008-05-25T15:24:00.001+08:00

Dynamic Host Configurations Protocol, also known as DHCP, is a network protocol that enables the DHCP server to assign an IP address to the networked devices or clients to obtain neccessary parameters in order to establish Internet Procotol (IP) network.

How does DHCP works ?

The client device turned on with DHCP client.
This client will broadcast a number of requests ( DISCOVER and DHCPDISCOVER ) packets in the network to look for reply from DHCP server.
The router ( if the router itself is not a DHCP server ) will route the DISCOVER packet to DHCP server.
Once the DHCP server received the DISCOVER packet, it will looks into the pre-configured policies and availability then determines the appropriate IP settings to assign to the client station.
The DHCP server will send an OFFER or DHCPOFFER packet to the client based on the MAC address with the neccessary parameters ( i.e. IP address, gateway, DNS, WINS etc. )
The client will send REQUEST or DHCPREQUEST packet back to the DHCP server and inform the server that it intend to use the configurations info offered.
The server will then reply with an ACK or DHCPACK packet back to the client and confirmed that the client may use the information for a certain period ( lease time ) as per configured in the policy.

More information on DHCP at Wikipedia

Linux Policy Routing : ip rule

2008-05-16T22:45:00.001+08:00

Policy based routing is actually an act of having a multiple routing table in a single machine. Normally, it is used when involving different routes and gateways.

Your kernel must be ready compiled with IP Advanced Router and IP Policy Routing in order to use this features.

To show the ip rule

# /sbin/ip rule show
0: from all lookup local
32766: from all lookup main
32767: from all lookup default

To show the main routing table

# /sbin/ip route list table main

203.158.11.16/29 dev eth2 proto kernel scope link src 203.158.11.17
192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.254
10.100.100.0/24 dev eth1 proto kernel scope link src 10.100.100.2
default via 203.158.11.22 dev eth2

The above shown, main table is actually refers to the main routing table when you type /sbin/ip route, whereas the local and default table is a new one.

You can generate rules which point to different tables ( i.e. xyz table ) which allow us to override system wide routing rules.

The first rule specifies that any packet from any where should first be matched against routes in the local routing table.The local routing table is for broadcast addresses on link layers, network address translation, and locally hosted IP addresses.

When a packet that bound for x.x.x.x IP address

The packet that bound for x.x.x.x would first pass thru the local routing table.
If there is no a local hosted IP address, it would look the main routing table to select a destination route.
If there is no host nor network match for this destination, thus the packet will match the default route in the main routing table.

To add a new table

# /sbin/ip route add 192.168.1.0/24 via 192.168.0.254 table 200

# /sbin/ip route add default via 10.100.100.1 table 200

To apply a rule to the newly added table 200

It means all the traffic from 192.168.0.0/26 will be routed via routing table 200

# /sbin/ip rule add from 192.168.0.0/26 table 200

# /sbin/ip route flush cache

*** Remember to flush the routing table cache ***

Therefore, you may have the followings results when you show your ip rules :

# /sbin/ip rule show
0: from all lookup local
32765: from 192.168.0.0/26 lookup 300
32766: from all lookup main
32767: from all lookup default

To delete a ip rule

# /sbin/ip rule del from 192.168.0.0/26 table 200

# /sbin/ip route flush cache

*** Remember to flush the routing table cache ***

It is quite troublesome if you need to type so many lines each and everytime the system is booted, thus you can actually put in a scripts. Below is some sample scripts :

#!/bin/sh
/sbin/ip route flush table 200
# Copy main routing table to 200
/sbin/ip route list table main |while read ROUTE ; do /sbin/ip route add table 200 $ROUTE ; done
/sbin/ip route replace default via 10.100.100.1 table 200
/sbin/ip rul add from 192.168.0.0/26 table 200
/sbin/ip route flush cache

Some other useful ip rule commands :

To change the preferences of the routing table

# /sbin/ip ru add from 192.168.0.0/26 pref 3500 table 200

0: from all lookup local
3500 : from 192.168.0.0/26 lookup 300
32766: from all lookup main
32767: from all lookup default

To create a NAT rule with ip rule

# /sbin/ip ru add nat 203.158.11.20 from 192.168.0.188

0: from all lookup local
3500 : from 192.168.0.0/26 lookup 300
32765: from 192.168.0.188 lookup main map-to 203.158.11.20
32766: from all lookup main
32767: from all lookup default

Usage: ip rule [ list | add | del | flush ] SELECTOR ACTION
SELECTOR := [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK ]
            [ dev STRING ] [ pref NUMBER ] [ prio NUMBER ]
ACTION := [ table TABLE_ID ]
          [ prohibit | reject | unreachable ]
          [ realms [SRCREALM/]DSTREALM ]
TABLE_ID := [ local | main | default | NUMBER ]

How to minicom serial console in Linux ?

2008-05-15T18:53:00.001+08:00

Firstly, you need to get ready with the tools as below :

RS232 Console Serial Cable
USB to RS232 Serial Cable convertor

Then, you will need to install minicom package into your linux. For debian user, you can install using aptitude or apt.

# apt-get install minicom

Then plug your USB to RS232 Serial Convertor into your USB port. The type # dmesg and you should see the followings text at the bottom.

usb 5-1: new full speed USB device using uhci_hcd and address 2
usb 5-1: configuration #1 chosen from 1 choice
usbcore: registered new interface driver usbserial
/build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/serial/usb-serial.c: USB Serial support registered for generic
usbcore: registered new interface driver usbserial_generic
/build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/serial/usb-serial.c: USB Serial Driver core
/build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/serial/usb-serial.c: USB Serial support registered for pl2303
pl2303 5-1:1.0: pl2303 converter detected
usb 5-1: pl2303 converter now attached to ttyUSB0
usbcore: registered new interface driver pl2303
/build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/serial/pl2303.c: Prolific PL2303 USB to serial adaptor driver

Identify where you USB convertor is attached to. From the example above, it is connected to /dev/ttyUSB0 *( Remember it, as you will be using this info later ).

Now, start to configure your minicom using su privileges by :

# sudo minicom -s

Then, select theSerial port setup.

Change your settings for Serial Device to /dev/ttyUSB0 ( or whichever is shown when you did # dmesg just now ) and also change the item (E), Bps/Parity/Bits to suite to your device. You may need to change other settings as per your requirements. Press ENTER upon complete.

Then, select Save setup as dfl and exit.

Now, you may start with your serial console communication by issue the following command :

# minicom

Done!

VLAN for linux

2008-05-13T22:36:00.001+08:00

What is VLAN ?

VLAN, Virtual Local Area Network, is somehow a several virtual network co-exist in a same switch port or interface by using the software configurations but not using hardware interface.

In the case whereby all workstations which connected to a same L2 switch in LAN X, are able to communicate within each other. If a workstation from LAN X is wish to communicate with LAN Y, then a router is needed.

VLAN, is actually an act of dividing the communications between few different network virtually by using a single switch device. A single switch port in a VLAN-capable switch can carry packets from multiple virtual LANs and linux can understand the format of these Ethernet frames.

VLAN, is known as IEEE 802.1Q and aslo known as VLAN tagging. More info on Wikipedia.

What are the advantages using VLAN ?

Performance
Easy to manage
Security
Trunks
Save the work of 'hardware configurations' whenever there is any changing of physical location for any device.

How to configure VLAN ?

The 802.1Q package has been pre-patch in kernel 2.4. Any distributions which are earlier than this, should download and compile/patch the kernel before proceed.

First of all, you need/must to modprobe the module by :

# modprobe 8021q

Then you should make sure the interface where you want to add the VLAN is UP and RUNNING.

For example,

2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:02:44:73:ed:64 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.254/24 brd 192.168.0.255 scope global eth0
    inet6 fe80::202:44ff:fe73:ed64/64 scope link
       valid_lft forever preferred_lft forever

To bring up the interface

# ifconfig eth0 up

# ip link set eth0 up

To bring down the interface

# ifconfig eth0 up

# ip link set eth0 up

Case 1 : You will want to add an VLAN 8 to interface eth0 and configure as 10.10.10.10/25 for this VLAN interface. Then remove it.

To add a new VLAN

# vconfig add eth0 8

To bring up the VLAN interface and configure IP

# ifconfig eth0.8 up

# ifconfig eth0.8 10.10.10.10 netmask 255.255.255.128 broadcast 10.10.10.127

To remove the VLAN interface

# vconfig rem eth0.8

How to dial PPPoE in Linux

2008-05-09T00:21:00.001+08:00

There are a few simple steps to make a pppoe connection in Linux.

** The following commands is based on Kubuntu distributions

First, you need to configure the pppoe configurations at the very first time using the following command using root provileges.

# pppoeconf

Then following the text-based menu screen will be shown and follow the instructions as below :

Confirm that your Ethernet card is going to connect to ADSL modem.
Enter your username ( i.e. justk2@streamx )
Enter your password.
If you have configured it before, you will be asked if it may be modified.
Popular options: you are asked if you want the “noauth” and “defaultroute” options and to remove “nodetach” - choose Yes.
Use peer DNS - choose Yes.
Limited MSS problem - choose Yes.
Then you are asked if you want to connect at start up.
Finally you are asked if you want to establish the connection immediately.
Once you have finished these steps, your connection should be working.

Next time, you may use the following command

To start the adsl dial up

# pon dsl-provider

To stop the adsl dial up

# poff dsl-provider

Linux Firewall : iptables - NAT

2008-05-08T23:53:00.001+08:00

What is NAT ?

NAT, refers to Network Address Translations, also known as network masquerading, native address translation or IP masquerading, is a method to translate/change the source or destination IP address when traffic passing through. It may also used for the TCP and UDP port of the passing IP packet.

Most of the time it is used to provide Internet access to a multiple LAN hosts by using a single Public IP.

What you must know ?

MASQUERADING

Masquerading is to translate all IP to a single IP and it is done with NAT. It is to fake the outgoing packet. The incoming packet should be translated too.

Masquerading works based on the specified interface.

Source NAT ( SNAT )

SNAT is when you alter the source address of the first packet: i.e. you are changing where the connection is coming from. Source NAT is always done post-routing, just before the packet goes out onto the wire. Masquerading is a specialized form of SNAT.

For dynamic Public IP case, whenever the source IP is changed, the source port numbers may changed too. Therefore, it is more easier to do SNAT on all outgoing packets on this interface. Also bear in mind, it would implicit DNAT as well and somehow.

Destination NAT ( DNAT )

DNAT is when you alter the destination address of the first packet: i.e. you are changing where the connection is going to. Destination NAT is always done before routing, when the packet first comes off the wire. Port forwarding, load sharing, and transparent proxying are all forms of DNAT.

What is important ?

The most important option here is the table selection option, `-t'. For all NAT operations, you will want to use `-t nat' for the NAT table.

You may need to specify the source ( `-s' or `--source' ) and destination ( `-d' or `--destination' ) of the packets you want to NAT. These options can be followed by a single IP address ( e.g. 192.168.1.1 ), a domain name ( e.g. www.justk2.com ), or a network address ( e.g. 192.168.1.0/24 or 192.168.1.0/255.255.255.0 ).

Lastly, you also need to specify the incoming ( `-i' ) or outgoing ( `-o' ) interface to match, but which you can specify depends on which chain you are putting the rule into: at PREROUTING you can only select incoming interface, and at POSTROUTING you can only select outgoing interface.

**If you use the wrong one, iptables will give an error.

Chains in NAT table

There are three (3) different chains in NAT table, which are PREROUTING, POSTROUTING and OUTPUT.

PREROUTING Chain

It is for Destination NAT, as packets first come in.

Destination NAT is specified using " -j DNAT ", and the " --to-destination " option specifies an IP address, a range of IP addresses, and an optional port or range of ports (for UDP and TCP protocols only).

Case 1 :

To DNAT all incoming packet at 203.158.26.29 at eth2 to the single LAN station 192.168.10.22.

# /sbin/iptables -t nat -A PREROUTING -i eth2 -d 192.168.10.22 -j DNAT --to 203.158.26.29

Case 2 :

To DNAT the incoming port 8080 at 203.158.26.29 at eth2 to the DMZ station 192.168.10.188 web server ( port 80 )

# /sbin/iptables -t nat -A PREROUTING -i eth2 -d 192.168.10.188 -j DNAT --to 203.158.26.29:8080

** This is known as Port forwarding.

POSTROUTING Chain

It is for Source NAT, as packets leave.

Source NAT is using " -j SNAT " and " --to-source " option specifies an IP address, a range of IP addresses, and an optional port or range of ports (for UDP and TCP protocols only).

Case 1 :

To NAT the LAN station ( 192.168.92.62 ) from eth0 to a static public IP or WAN IP ( 203.158.26.29 ) at eth2

# /sbin/iptables -t nat -A POSTROUTING -o eth2 -s 192.168.92.62 -j SNAT --to 203.158.26.29

Case 2 :

To NAT the entire LAN network ( 10.10.10.0/24 ) from eth1 to a range of WAN IP ( 203.158.26.29 ~ 203.158.26.32 ) at eth2

# /sbin/iptables -t nat -A POSTROUTING -o eth2 -s 10.10.10.0/24 -j SNAT --to 203.158.26.29-203.158.29.32

Case 3 :

To NAT the LAN network to a dynamic WAN IP i.e. PPP connection.

# /sbin/iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE

OUTPUT Chain

It is for the firewall or router itself.

FOUR steps to makes your NAT works

Forward the traffic

If you are using the Linux kernel more than 2.6, the following commands should works.

Firstly, you should allow the traffic to forward ( passing ) through your firewall/router. By default, the value is 0 which is disabled.

# echo 1 > /etc/sys/net/ipv4/ip_forward

In some cases, you may need to edit /etc/sysctl.conf and change the line that says net.ipv4.ip_forward = 0 to net.ipv4.ip_forward = 1. This essentially tells your kernel to do step one on boot.

** Also remember to accept the traffic passing in your forward chains ( more info as my earlier post )

# /sbin/iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT

# /sbin/iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT

Post-route the traffic

# /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

Linux Firewall : iptables - FILTER table

2008-05-01T01:10:00.002+08:00

Further to the basic understanding on the iptables in my earlier post ( Linux Firewall : iptables - Basic ), now let's me continue with some example commands for FILTER table :

To list the iptables table/chain

#iptables -L

#iptables -t <table> -L

( use to list the specify table besides default - FILTER table )

#iptables -t <table> -L -vnx

( use this with verbose, show numeric output and expand the numbers )

To add a rule on top of the chain

#iptables -I <chain> -j [ACCEPT|DROP|REJECT|other]

e.g. # iptables -I FORWARD -j ACCEPT

To append a rule at the bottom of the chain

#iptables -A <chain> -j [ACCEPT|DROP|REJECT|other]

e.g. # iptables -I INPUT -j DROP

To delete a rule in a chain

#iptables -D <chain> <the row number of the rule started from 1>

e.g. # iptables -D FORWARD 2

To create a new chain

#iptables -N <chain>

e.g. # iptables -N CUSTOMFORWARD

To change the default policy of a chain

#iptables -P <chain> [ACCEPT|DROP|REJECT|other]

e.g. # iptables -P FORWARD DROP

# iptables -P CUSTOMFORWARD ACCEPT

To flush the iptables

#iptables -F

To flush specify TABLE

#iptables -t <table> -F

To delete a CHAIN

#iptables -X <chain>

So, have you warmed-up? Now let's go into more commands, try to understand and apply it wisely. :P

Case 1

To drop all the traffic from 192.168.0.0/24 which trying to ssh-ing to the firewall itself, 10.133.0.1

# iptables -I INPUT -p tcp --dport 22 -s 192.168.0.0/24 -d 10.133.0.1 -j ACCEPT

-I = to add this rule to the top of INPUT chain.

-p = protocol, specifically here is TCP.

--dport = destination port, specifying SSH port ( port 22 ).

-s = the source address, pertaining where this traffic from where is 192.168.0.0/24 for this rule.

-d = the destination address, here is the firewall itself (suppose) as it is INPUT chain.

-j = jump to targer. Here is to accept the traffic.

Case 2

To drop all the traffic from 192.168.0.0/24 passing thru the firewall and only allowed 192.168.0.188 to pass thru.

# iptables -P FORWARD DROP

# iptables -I FORWARD -s 192.168.0.188 -j ACCEPT

# iptables -I FORWARD -d 192.168.0.188 -j ACCEPT

Firstly, we set the FORWARD as "default drop policy" ( means drop everything! ). Then we add the 2 following rules on top of the FORWARD chain. In order to allows the traffic passing thru, it should be dual-way. Thus, two(2) different rules as above are created with specifying source and destination address respectively.

General Network Traffic rules

Next, we will want to use some standard rules for general network traffic. This goes a bit beyond the basic stuff, however iptables can determine the 'state' that a packet is in. This has to do with standard TCP communication. For example, the 3 way handshake between two hosts when transmitting data.

NEW => Server1 connects to Server2 issuing a SYN (Synchronize) packet.

RELATED => Server 2 receives the SYN packet, and then responds with a SYN-ACK (Synchronize Acknowledgment) packet.

ESTABLISHED => Server 1 receives the SYN-ACK packet and then responds with the final ACK (Acknowledgment) packet.

After this 3 way handshake is complete, the traffic is now ESTABLISHED. In order for this type of TCP communication, something similar to these three rules are necessary:

# iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT # iptables -A FORWARD -i eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT # iptables -A OUTPUT -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT

The last rule obviously allows any traffic the leave the server.

The result of the three rules and the previous commands in Case 1 and Case 2 above will be as follow respectively :

Chain INPUT (policy ACCEPT) target prot in out source destination ACCEPT tcp * * 192.168.0.0/24 10.133.0.1 tcp dpt:ssh ACCEPT all * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED

Chain FORWARD (policy DROP) target prot in out source destination ACCEPT * * * 0.0.0.0/0 1 92.168.0.188 ACCEPT ACCEPT * * * 192.168.0.188 0.0.0.0/0 ACCEPT ACCEPT * eth0 * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED

Chain OUTPUT (policy ACCEPT) target prot in out source destination ACCEPT * * * 0.0.0.0/0 0.0.0.0/0 state NEW,RELATED,ESTABLISHED

From here you can add whatever rules you like depending on your server requirements :

To block some BAD source IP address

#iptables -A INPUT -s 10.10.132.2 -j DROP

To drop some spamming from a source IP address ( if you are using default accept policy or accepted SMTP port in other rule )

#iptables -A FORWARD -p tcp --dport 25 -s 192.168.0.111 -j DROP

To allow the LAN (eth0) to access your web while block all external access from WAN(eth1) to your web

#iptables -I INPUT -p tcp --dport 80 -j DROP

#iptables -I INPUT -p tcp --dport 80 -s 192.168.0.0/24 -j ACCEPT

The 1st rule should be execute before the 2nd rule as you are using the -I ( add ).

To drop all ICMP/Ping packet to the firewall

#iptables -A INPUT -p icmp -j DROP

If you are using the default ACCEPT policy, then you must be DROP anything else at the last of the rule. In our case here ( since FORWARD chain is default drop policy ), you should reject everything for the INPUT chain.

# iptables -A INPUT -j REJECT

There are more to explore besides the example shown above. But bear in mind, ***NEVER TRY ON A LIVE SYSTEM!!***

In the next post, I will proceed to NAT table.

10 things to consider when choosing a Linux distribution

2008-04-26T19:31:00.001+08:00

Date: April 9th, 2008
Author: Jack Wallen

I can’t begin to tell you how many people over the years I have consulted with about choosing a Linux distribution. And even with my own personal loyalties to one distribution or another, it always amazes me how certain distributions are better suited to various users and needs. So when I set out to write a 10 Things article, it only made sense that my first one be related to choosing a Linux distribution.

Of course, times and opinions change. For nearly 10 years I road the Red Hat/Fedora wagon. And then, after considerable thought, I jumped over to Ubuntu. Why? Because it fit my evolving needs. Many will argue that one Linux distribution is just like another — and I agree, on fundamentals. But when it comes down to everyday use, each distribution is different from the next. So why would you want to use Debian vs. Fedora or Ubuntu vs. Mandriva? Let’s dive into this and find out.

Note: This information is also available as a PDF download.

#1: 100 % open or not?

Many people don’t seem to know this question even exists. Average users may think that all Linux distributions are created equal, since they are released under the GPL. They are not. Some distributions are being released with proprietary drivers. In some instances, these are necessary. For example, for many laptops, getting wireless to work often requires the use of a proprietary driver. Because of this, some Linux distributions are opting to make the inclusion of proprietary drivers the user’s choice. And many of these distributions are even offering downloads of free and non-free (with regards to licenses, not cost) drivers.

If you champion 100% free software, you’ll want to look at the following:

Those are the only distributions that don’t offer any releases with non-free software. You can also get versions of distributions like Mandriva Free, which are bereft of non-free applications. This choice will be dictated by two things: the “politics” of Linux and the need for proprietary drivers.

#2: Package management

This is one of those areas where people begin to leap up on their soapboxes. RPM vs. Apt vs. dpkg vs. urpmi. Some would say that they are all fundamentally the same: Each has a command-line tool as well as a GUI front end, and each has a configurable repository system that can be edited by hand (via text editor) or through the GUI front end. I will argue (not that I have become a Ubuntu convert) that the Apt system is much better as a package management system. I say this because RPM has a tendency to be unable to resolve dependencies, as well as to muck up a system over time. But for the average user, the biggest (and probably most crucial) difference lies in the GUI front ends. Between managers like Synaptic and GnoRPM, there is no comparison. Even after nearly 10 years of working with Linux, I have never found a stable front end for RPM. Apt front ends, on the other hand, have enjoyed stability for a long time.

So if you prefer one package management system over another, your choice will already be narrowed down. Of course, it can get a little murky with crossovers, like apt-rpm. But if you want Apt, you will be using a Debian-based system. If you want RPM, you will be using a Red Hat/Fedora-based distribution (or, in the case of urpmi, Mandriva.)

#3: Directory hierarchy

This is one of those issues that has always befuddled me. There should be a standard that all distributions stick to. But as it stands, there is not. Take the init system (the initialization system). In Fedora-based systems, you will find this in /etc/rc.d/init.d. In Debian-based systems, you will find this in /etc/init.d. Even the Linux Standards Base does not define where the initialization system should lie. But you will still have your own personal standard. When moving from Fedora to Ubuntu, it took me a while to keep from typing /etc/rc.d/init.d/mysql start and typing /etc/init.d/mysql start. If you’re used to one, either stick with it or anticipate a few “command not found” errors.

#4. Desktop environment

Although you can install your desktop of choice, some users just want to install the OS and go. In that case, you will want to make sure you choose a distribution that focuses on the desktop environment you like. If you want GNOME, go with Fedora. You can check out this listing of distributions shipping with GNOME as the default. If you want KDE, check out this listing of distributions shipping KDE as the default. Of course, you are not limited to either GNOME or KDE. My preference is for Enlightenment. Some distributions ship with Enlightenment as the default, such as Elive and gOS.

Even though it’s possible to install the desktop of your choice, it’s not always as simple as it might seem. If you don’t want to spend time resolving dependencies or figuring out what repository to add to install KDE4, go with a distribution that ships your preferred desktop by default.

#5: Security

Linux is a much more secure OS than most, although not all distributions are equally secure. In fact, there are distributions aimed primarily at security, such as Trustix, which claims to be the most secure of all Linux distributions. But truth be told, the most secure Linux distribution is the one that is properly configured. But if you want security “out of the box,” the short list of distributions would include Trustix, Engarde Linux, and Bastille Linux.

#6: Intended use

Let’s face it: We don’t all use our computers for the same thing. Some need multimedia. Some need servers. Some need development. Some need a simple workstation to write and surf the Web. And there are Linux distributions for every need. Need a headless server? Give Ubuntu Server Edition <http://www.ubuntu.com/products/whatisubuntu/serveredition> a try. Is multimedia your game? If so, take a look at StartCom Multimedia Edition. If you’re an average user (office suite, e-mail, Web), you can go with any of the distributions.

#7: Hardware

This one is tricky. As I said earlier, your hardware will sometimes dictate what drivers you will use. But it goes beyond that. There are distributions that are known for their hardware friendliness. For instance, PCLinuxOS is one of the best choices for overall hardware detection and setup (as well as being one of the simplest to install). For wireless, your best choices are Ubuntu, Mepis, and SuSE.

#8: Laptop use

Another tricky spot. On top of having to deal with wireless and graphics (see #7), you also have to hope that your laptop will support hibernation. This is one of the rougher spots for modern Linux. Getting a laptop to suspend or hibernate is a matter of hoping your particular laptop will play well with your distribution. Your best bet is to simply Google your make and model of laptop along with “linux suspend” to find out which distribution is best suited for your machine.

Wireless on your laptop will be an interesting journey. But here’s a good tip to help you out: Forget tools like Exalt and go directly to WICD. This tool is much better at handling various forms of wireless authentication.

#9: Installation

If you are really considering Linux, you know you have two choices: Find a vendor that will sell you a machine with a pre-installed distribution or install a distribution yourself. If you have never installed an operating system, don’t fret; it’s not hard. It will take some time, but rest assured that all modern Linux distributions (with the rare exception) are point-and-click GUI installations. And Linux one-ups its competition by giving you the Live CD. You can pop it into the machine, boot from it, and give Linux a try without having to install anything. A Live CD instance of Linux will run considerably slower than the installed version (and that will depend upon how much RAM your machine has), but you can get a good idea how well it is going to react to your hardware (and how you are going to react to the OS).

I would like to say that one distribution’s installation routine is better than another (to help you weed out possible hurdles in your adoption of Linux). But that is not so much the case now. Personally, I prefer the installations of Ubuntu (in its many incarnations) and Fedora to any other. I find their installations to be far more intuitive and user friendly.

If installation isn’t your game, just find a vendor that sells Linux pre-installed. You can go to online dealers like Hewlett Packard, Dell, Zonbu, Everex, and many others. This will keep you from having to dance around distributions to figure out which will support your hardware.

#10: Community

This aspect is a bit esoteric, but it should be addressed. Linux is more than an operating system. Linux, akin to Apple, is a community. Linux is about freedom and its communities embrace that — some more than others. So if community (feeling like you belong to something special) is important to you, Ubuntu is the distribution for you. If not, you could go with the more enterprise-level Red Hat, where you’ll enjoy a more traditional model of both customer service and support.

Which brings up a related issue: Support. Along with Linux comes many forms of support. Each distribution has its own mailing list, where you can enjoy hundreds (or thousands) of users who range from every level of experience. If you’re a DIY kind of person, this type of support will be right up your alley. And it’s free! If you’re not the DIY type, you should stick with SuSE (which benefits from Novell’s backing) or Red Hat, where you can buy a solid support package for your installations. If you do opt for the more community-drive distribution, you’ll be in good hands. On many occasions I have enjoyed speaking directly to the developer(s) of the application in question. Finding such a communication line with, say, a Microsoft or an Apple wouldn’t be so easy. With Linux — you never know. You might wind up chatting up the Linux kernel with Linux creator Linus Torvalds himself. I have a few times.

So there you have it. Ten things to consider when choosing a Linux distribution. But ultimately, it all boils down to choice. And that’s where Linux really shines. With Linux, you can choose on nearly every level. You aren’t locked down to any one thing.

Original Post : http://blogs.techrepublic.com.com/10things/?p=334