Gotta be the best Cisco Router Simulator Ever

GNS3 Against Packet tracer 5.1

GNS3:
1. You can almost do all the commands that the packet tracer cannot do.
2. You can simulate the virtual network to a real hardware or an equipment.
3. The frame cloud is easier to configure.
4. Free

Packet tracer 5.1:
1. Limited commands only
2. You can only connect directly to another workstation.
3. Frame cloud is a bit hard to configure and understand.
4. Available only to those enrolled in CNAP.