Difference between Protocol number and Port number

Protocol number is the value contained in the “protocol” field of an IPv4 header. It is used to identify the protocol. This is an 8 bit filed. In IPv6 this field is called “Next header” field. Some of the protocol numbers of commonly used routing protocols are given below:

Protocol	Protocol Number
EIGRP	88
OSPF	89

Different types of communication systems

Simplex

In this type of communication, first device send data and second device receive it. Second device never send  any information to first device. Broadcast systems like FM radio work in this way.

Half Duplex

In this type of communication, when first device send data, second device receives it and when second devices send data, first device receives it. But both devices can’t send or receive data at the same time. This type of communication is using in "walkie-talkie".

Full Duplex

In this type of communication, first and second device can send and receive data simultaneously. Phones and mobile phones are using this type of communication.

Note: In Ethernet communication we can set both end half or full duplex depending up on the requirements. That is Ethernet can work on both mode.

Installing and configuring SecureCRT for gns3

Secure CRT Installation

1. Download secureCRT with crack from internet (There are plenty of places, use google to search “SecureCRT with crack downlaod”)
2. Install secureCRT
3. copy the crack to installation directory (eg: C:\Program Files\VanDyke Software\SecureCRT\)
4. Run the crack as administrator (Right click the crack and in the menu select run as administrator)
5. Enter anything in name and company field and press generate. Now, the serials and other information appears.
6. Press the patch button to patch the secureCRT.exe file. That’s it.  Now the secure CRT installed correctly.

GNS3 configuration of secure CRT

1. Download and install GNS3, add IOS etc.
2. Go to Edit > Preferences > General > Terminal settings tab > SecureCRT > Change preconfigured terminal commands to SecureCRT (64 bit or 32 bit depending upon the version installed) > Press “use” button > press ok
3. Now add some routers (with IOS added) to work space and turn it on.
4. Press the console button to see the tabbed windows for each router

Note: if any error occurs, check the installation path of SecureCRT in the terminal command

asterisk with GUI (Asterisknow)

Now install and manage the open source PBX Asterisk with GUI!!!!!!!!

Download Asterisknow form here :

32 bit version: http://www.asterisk.org/downloads/asterisknow/i386/asterisknow32.iso

64 bit version: http://www.asterisk.org/downloads/asterisknow/x86_64/asterisknow64.iso

Find the installation date of an OS

Go to command prompt and run the following command:
systeminfo | find /i "install date"

Bluefish……A great free Linux/Windows Editor

Included language definition files for:
    * C/C++
    * CSS
    * CFML
    * gettext PO
    * HTML
    * Java
    * JavaScript
    * JSP
    * Perl
    * PHP
    * Python
    * Ruby
    * Shell
    * SQL
    * XML
and plenty more features.

Go to http://bluefish.openoffice.nl/ for more details  and installation instructions