Concepts / Forwarding

Forwarding

Router

Also called layer 3, forwarding, ip_forward

A device on several networks that forwards packets between them, by destination address.

For each packet it looks up the destination in its routing table, lowers the TTL by one, rewrites the frame's MAC addresses for the next link and sends it on. A host becomes a router when forwarding is turned on (net.ipv4.ip_forward).

See it on real machines

Learn it on real machines.

Every lab is a small network of real Linux machines in your browser. Start with a free account: Google or email, no card.

Start this lab, free