On a complex networking environments, investing to physical devices before doing a solid planning is almost never a good approach.

Thankfully, there are solutions to this issue. Actually, multiple ones. The keyword for all solutions is virtualization. Why not to simulate and optimize physical network environment as close as you can before investments? And playing with networks, it can be both fun and challenging.

This post covers basic idea of GNS3, an open-source network virtualization solution. In GNS3, simulated networks can, if allowed, access physical networks and vice-versa + you can use real (virtualized) operating systems in addition to router, switch and firewall software.