ip forwarding-protocol.

Hi,

say you have enable NetBIOS over udp in your lan A and want the computers of this lan to communicate with the computers of lan b, now if you need to cross a couple of routers for this (say you have a to cross a leased t1) you will need ip forward-protocol udp 137 and 138 so the routers will forward the udp broadcasts received on those ports, otherwise the nature of the router is to drop such packets. This is just an example but the full command functionality is to relay those broadcasts to other networks. Hope it helps.

Router is designed to localise the broadcast/multicast .

So if you want to forward any broadcast udp etc then this command is used .

HTH