Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I want to study network. But I don't have an access to a sample network (routers, DNS, IP4, IP6 windows linux mixed heterogenous system). Do you know any online network to study (Free as possible). Is it possible to simulate network topologies with a single PC using virtual machine. If so could you guide me?

share|improve this question
up vote 8 down vote accepted

If you're looking for a networking lab, you should look into PacketLife Community Lab.

share|improve this answer


GNS3 is a graphical network simulator that allows simulation of complex networks.

share|improve this answer
Can I use it without IOS images, in other words, can I use Linux VMs as routers? – Hubert Kario Jan 30 '11 at 13:45

If you're looking at learning about routers and networking on that level, it's hard to beat DynaMIPS and Dynagen as a free resource. You still need to get hold of one (or more) IOS images to run on your virtual Cisco routers and some things are hard to do within DynaMIPS.

It doesn't support emulating switch hardware (due to the high amount of very specialised silicon in a Cisco switch), so it's hard to experiment with VLANs (some things can be done using multi-port ethernet cards and doing VLANs there, but some VLAn functionality (private VLANs being one) can only be done in switch IOS).

While you can implement QoS policies, it's not necessarily easy to test them for accuracy within a DynaMIPS set-up.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.