Open-Source Network Simulators?

[dcarr3311]

what is a good graphical network simulator? I've played  around with GNS3, but is there something that supports Nexus? and ASR routers?

thanks 

Dan

[vivek srivastava]

Not seen any other open-source simulators which supports nexus as well as XR. However there are some ways where you can simulate XR in GNS using XRv over Virtual-Box.

If you are ready to pay then use official cisco virtual lab. it supports all.

http://virl.cisco.com/