BOGDAN OVIDIU S... Sat, 03/21/2009 - 10:40


There is a very good simulator for Cisco routers called Dynamips. You can use a text-based front-end ->Dynagen, or graphic ->GNS3

It works on Windows and Linux.

But more info:

All the best,


badalam_nt Sat, 03/21/2009 - 14:14

You could check for any detail the link provided by Bogdan.

Just to mention that GNS3/Dynamips is an emulator, unlike PacketTracer or Boson etc, which are simulators.

It runs the real IOS (so you need to have the IOS image of the router you want to run on GNS3) under Windows or Linux, taking up some important amount of system RAM and CPU, so you need to tweak it in order to be able to run several routers. At that link you'll find all the needed info and step-by-step installation and usage guide. You could find as well discussions around GNS3 on several forums which could help as well.

jimmysands73_2 Sun, 03/22/2009 - 12:27

Aside from the computer engineering arguments about whats different from a simulator vs. emulator....from a students point of view, whats can be more helpful in a emulator vs. a simulator?


BOGDAN OVIDIU S... Mon, 03/23/2009 - 11:21


Dynamips/Dynagen (GNS3)lets you play with the real CISCO IOS, not a simulation of the IOS as Packet Tracer.

Packet tracer is a very good tool, but it has a lot of restrictions compared with the real IOS.

Of course, you can use any tool (GNS, Packet Tracer) depending on your needs and time.

Try the documentation, look for topologies, already made for dynamips/dynage or GNS3, over the internet.

Here is a very good topology made by the guys from InternetworkExperts, and nice info:

Dynamips/Dynage or GNS3, they all have a small "problem": it emulates only the routers, not the switches. There is a workaround also: put a switch module (16-ESW, I think)in the router and you have also a switch. But with router IOS CLI.

Have "fun" with both simulator & emulator!


jimmysands73_2 Sun, 04/05/2009 - 08:19

Does Dynamips/Dynagen support frame-relay? Packet Tracer doesnt handle frame-relay (frame-relay switching command) very well.



BOGDAN OVIDIU S... Tue, 04/07/2009 - 11:23

Yes! You can make a router as a frame-relay switch.

In GNS3,there is a frame-relay switch already made. It works fine! (But you can also make your own.)

I use GNS3 in my study for ccie.



jimmysands73_2 Thu, 04/09/2009 - 11:52

I tried it last night, does look alot more powerful than PacketTracer...but I have to get some IOS code, as when I tried to get to a router, it wouldnt let me as I had to invoke the code....for every device...I am going to get some from school and use it, thanks for the info.


This Discussion