What's a good, free router emulator?

[SSSnail]

Thanks, even an eval is good.

 

[jlazzaro]

Cisco emulator (eSIM) or the Boson emulator.

 

[James Bond]

I really liked Boson.

 

[alfa147x]

So what are these emulators used for?

 

[jlazzaro]

more for CCNA (possibly CCNP) practice than anything. Create a topology of routers and switches with different ethernet and serial interfaces. Connect them with logical media and practice show, config, and interface commands on them without spending $$ on hardware.