Computer emulator Network is console emulator for Linux and Cisco IOS command line enviromnents

Computer Network Emulator has been developed on CVUT FEL mainly as part of a few diploma theses. The purpose is to enable you to configure network simulations using command line commands simulating Linux and Cisco IOS environments. It is using graphical Omnet++ simulation environment. Networking modules are based on standard INET framework, however some modifications are performed to the original code, because of need for runtime configuration support. INET and especially Omnet highly depends on static initialization of modules at the beginning of simulation.

At current release, the emulator supports subset of IPv4,IPv6 and link layer configuration commands for Linux and Cisco IOS environments.

Installation of Computer Network emulator is same as installation of Omnet. The build system is modified to keep simplicity. First of all, prerequisities must be done.

 $ sudo apt-get update
 $ sudo apt-get install build-essential gcc g++ bison flex perl \
 tcl-dev tk-dev blt libxml2-dev zlib1g-dev openjdk-6-jre \
 doxygen graphviz openmpi-bin libopenmpi-dev libpcap-dev
 

After this step we should have done all necessary prerequisities configured. The next step is to setup environment variables. This is done by typing

 . setenv
 

into the console. This script setup root directory as current working directory and few other things. You can do this also by hand, if necessary. The next step after that is to run script configure. this is done by typing

 ./configure
 

into to console. This script check all necessary things that are needed for build. If error occures during this phase, it's probably because of missing installed prerequisities or environment variables are not configured, or configured incorrectly. The script print error message about what goes wrong (and if something is wrong with environment setup, print help how to fix it). It wverything goes smoothly, then build system of emulator is prepared.this done by

 make makefiles
 make
 

typed into console. First command causes generation of makefiles in src directory of emulator(Omnet). It also causes generation of makefiles in samples directory, where is our inet framework modified within our emulator modules. Next typing make into console run build of emulator. After this step we are prepared for runing emulator by typing into console command

 omnetpp
 

Now emulator starts, if nothing goes wrong. Sometimes is needed to change #include directives location and also linkage libraries.

Installation steps on Windows OS are same as installation of Omnet. So you can watch for reference to omnet guide and follow the steps.

After installation you must assemble simulation network using prepared CNE modules. As a first touch with simulation, you can choose some example networks. This is the best way to start with emulator.

Next step is to start configuring emulator. First of all you need to connect to some of configurated nodes. In simulation window choose from context menu open console. Next you can connect to the linux modules by typing ssh <node_name> , where node_name is name of node you want to configure. now you are on emulated linux device and you can start typing commands. Connecting to the cisco device is similar. You must type telnet <node_name>, where node name is cisco device. Same as previous example you can start configuring device.

C++ files and NED files documentation can be found in INET\doc folder, where is HTML page that is generated from source code annotations using doxygen and OMNET documentation tool. Source code of CNE modules is anottated with comments that are used for this documenation generation. There is also slightly modified homepage that contains basic info about emulator and link to current code changes is included.

Source code with emulator is located in GIT repository on address kttmine.fel.cvut.cz/git/cne-ipv6-extension.git . You need to have account for this repository. If you have, then you can obtain source code (Full emulator, not only IPv6 Extension) by typing:

 git clone https://username@kttmine.fel.cvut.cz/git/cne-ipv6-extension.git

Jan Michek thesis about CNEhttps://dip.felk.cvut.cz/browse/pdfcache/michej1_2008dipl.pdf

Pavel Jenicek thesis about porting emulator to Omnet 4.1 https://dip.felk.cvut.cz/browse/pdfcache/jenicpav_2012dipl.pdf

Martin Macura thesis about CNE IPv6 Extension https://dip.felk.cvut.cz/browse/pdfcache/macurma1_2013dipl.pdf

Linux ip2suite commands referencehttp://www.redhat.com/mirrors/LDP/HOWTO/html_single/Linux+IPv6-HOWTO/

Cisco IOS ipv6 commands reference http://www.cisco.com/en/US/docs/ios/ipv6/command/reference/ipv6_cr_book.pdf

linux ifconfig manpage http://linux.die.net/man/8/ifconfig