I understand that Packet Tracer doesn't support all of the commands for that particular exam.

I know GNS3 doesn't support switches either, however is it possible to load switch modules into the routers and perform switching like we would in actual switches?

Would all the commands be supported in GNS3? What specific switch module am I looking for?

I'm kind of short on cash and can't afford L2/L3 switches to practice on.

Yes I know about the community lab :), I just won't always have internet access.

You need to use a NM-16ESW module on one of the supported routers.

http://www.blindhog.net/gns3-how-to-build-a-switching-lab/

There a big caveat on GNS3. If you give the command "no shut" on an interface, it would give you status of up. Why is this a problem? Because with a real equipment, it would say line protocol is down when there's no neighbor on the other side that didn't have the "no shut" command given.

On frame-relay I've configure the clock rate on both ends and didn't give me an error. Usually when I do this on real equipment, the DTE end would scream at me and say its not a DCE and therefore cannot set clock rate.

Its always in up state whether if the neighbor is up or down when you turn on an interface. This causes problems because Cisco wants to know how a messed up configuration looks like. No, this is not a NDA violation - if you have worked with the Net Academy books, they make you break the configuration and observe the show command output.

So when do you have a chance, hop on the community lab. Remember know where to configure them (global or interface level) and which switch to configure them - this is especially true when it comes to spanning tree. Also with all Cisco exams/real world scenarios, always know your default values/behaviors.

Hope this helps

There are a lot of limitations in addition to what CaptnAmerica mentioned, especially in the switching exam.

Like, you will not be able to experiment all the functionality and features of STP, RSTP is not available at all, MST is not available as well.

There are limitations in the emulating of Etherchannel, LACP and PAgP.

Not all features are available in switching port security and VACL.

I hope you cover all features theoretically and focus more on that rather than wasting your time with fake equipment emulated, that particular exam is not possible to cover even 40% of its practical sections using GNS3. Otherwise you have to rent a LAB time online or build your own switching LAB or use some equipment of your friend ;)

Regards, Laith