Hack the Route Start free Open app Forwarding
MPLS
Forwarding by a short label put in front of the IP header, instead of by the destination address.
The ingress edge pushes a label; each core router looks only at the label, swaps it for its next hop's, and
passes the packet on; the label is popped at the end, usually one router early (penultimate hop popping, asked
for with the reserved label 3, implicit null). The path is a label-switched path (LSP), one way only. Labels mean
something only between two neighbours. Providers build VPNs, traffic engineering and fast reroute on it. In Linux:
ip route … encap mpls pushes, ip -f mpls route is the label table.