Sup guys,
Since this networking area is new, I thought I'd throw in Cisco Packet Tracer for those who cannot directly access it from the network academy itself. I've scoured the web for the latest version and I keep being taken back to versions 5 and under.
I have only tried packet tracer and have not tried any other network simulators, for that reason I'll ignorantly tell you it's better.
Provided in the links below are Packet Tracer 6.1.1 and 6.2 for both Linux and Windows:
Cisco_Packet_Tracer_6.1.1.tar.gzCisco_Packet_Tracer_6.2.tar.gzCisco_Packet_Tracer_6.2.exeCisco_Packet_Tracer_6.1.1.exe