Simulation

Network  Simulation

In communication and computer network research,Network simulation is a technique where a program models the behavior of a network either by calculating the interaction between the different network entities (hosts/Routers, data links, packets, etc.) using mathematical formulas, or actually capturing and playing back observations from a production network.  Reference

Network simulator 

 

A network simulator is a piece of software or hardware that predicts the behavior of a Network, without an actual network being present. A network simulator is a software program that imitates the working of a computer network. In simulators, the computer network is typically modelled with devices, traffic etc. and the performance is analysed. Typically, users can then customize the simulator to fulfill their specific analysis needs. Simulators typically come with support for the most popular protocols in use today, such as WLAN, Wi-Max, UDP, and TCP.

Many types of Network Simulators is available like (ns2/ns3, NetSim, GNS3 , Packet-Tracer etc).  GNS3 is one of the best network simulator, most of simulation could be do by. but no functionality is available for switches.However some we can.

GNS3

GNS3 is a graphical network simulator that allows simulation of complex networks. It is a Open-source software.

GNS3 network simulator can be download : Click here

         
To Simulate the GNS3 we need the Cisco IOS image as per the model which is provided in the GNS3.

To Download (Save as target to download) IOS image for GNS3 below links are available :--

For Routers

Cisco IOS c1700    -  c1700-adventerprisek9-mz.124-1a.bin
Cisco IOS c2600    -  c2600-adventerprisek9-mz.124-17.bin   
                             or  c2600-advsecurityk9-mz.123-12.bin
Cisco IOS c2691    -  c2691-advipservicesk9-mz.124-15.T6.bin
Cisco IOS c3640    -  c3640-jk9s-mz.124-16.bin
Cisco IOS c3660    -  c3660-telcoentk9-mz.124-13b.bin
Cisco IOS c3725    -  c3725-adventerprisek9-mz.124-25;).BIN
Cisco IOS c7200    -  c7200-adventerprisek9-mz.124-24.T.bin

For Firewalls

Cisco IOS PIX            -  Pix803.rar
Cisco IOS ASA802    -  ASA802.rar ASA
       
 Enjoy!!!!!!!!!........