Securing yourself from a world of hackers

*Above = Copy Pasted from other’s post.

Also check out my earlier post Good Password Practices

Life before the computer

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

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

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.

Gender Analyzer

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

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.

The Father of Spam

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!

Read more from...

Reaction to the DEC Spam of 1978 ,

The Father of Spam

What is FXO and FXS ?

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 :

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

When there is an inbound call :

1. When FXS received an incoming call, it will generate a DC ring voltage to the FXO device.
2. The FXO device ( phone ) will rings.
3. 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

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 :

1. Time-of-day restriction.
2. Physical location restriction.
3. Restrictions again multiple login at a single point of time.
4. 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?

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 ?

1. The client device turned on with DHCP client.
2. This client will broadcast a number of requests ( DISCOVER and DHCPDISCOVER ) packets in the network to look for reply from DHCP server.
3. The router ( if the router itself is not a DHCP server ) will route the DISCOVER packet to DHCP server.
4. 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.
5. 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. )
6. 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.
7. 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

OSI Model Standard

Basically all the networks todays are based on the OSI ( Open Systems Interconnection ) seven-layers Model which was developed by the International Organization for Standardization (ISO).

OSI Reference Model is a set of seven (7) layers that defines the staged that data must go through from one device to another over a network.

Layer 7 : Application Layer

This  layer is actually interacting with the Operating Systems. It is totally all applications and all related network protocols.

Protocols : DNS, FTP, HTTP, SNMP, SMTP, TELNET, SMB etc.

Layer 6 : Presentation Layer

This layer only responsible to translate/convert the data from Layer 7 to Layer 5 or vice versa into a standard format where the other layer can understand.

Layer 5 : Session Layer

This layer manages the data flow from higher layer to the lower by managing the data transmission timing. It also actually establishes the connections with another nodes.

Protocols : NETBios etc.

Layer 4 : Transport Layer

This layer would control the data flows control and provide error checking and recovery of data between devices.

Protocols : NETBios, TCP, UDP, RSVP etc.

Layer 3 : Network Layer

This layer determine the way that the data will be sent to the recipient device. Logical protocols, routing and addressing are handled here.

Protocols : IP, OSPF, BGP, IPSec, IS-IS, RIP, ICMP etc.

Layer 2 : Data Layer

In this layer, the appropriate physical protocols is assigned to the data. The type of network and the packet sequencing is defined here.

Protocols : WiMAX, Ethernet, PPP, L2TP, 802.11, FDDI etc.

Layer 1 : Physical Layer

This layer is actually the actual hardware with physical characteristics of the network such as connections, voltage etc.

Protocols : Modems, Optical Fiber, Twisted Pair etc.