A router uses the IP RIP information to inform the other routers in the network of the routes it finds in its own static table. The following entries are ignored:
- Rejected routes with the '0.0.0.0' router setting.
- Routes referring to other routers in the local area network.
- Routes that link individual computers to the LAN via proxy ARP.
Although the entries in the static routing table are set manually, this information nevertheless changes depending on the connection situation of the routers, which in turn influences the RIP packets transmitted.
- If the router has established a connection to a remote site, it uses RIPs to propagate all of the networks that can be reached over this route and gives them the distance '1'. This informs other routers in the LAN that a connection to this remote site is available using this router. This saves other routers from accessing their dial-up connections, which in turn reduces connection costs.
- Furthermore, if this router is unable to connect to any other remote sites, all of its other routes are propagated by RIP with the distance '16'. The '16' stands for "This route is not available at the moment". The following causes may prevent a router from establishing a further connection in addition to its current one:
- All other channels are busy with another connection (including via LANCAPI).
- Y-connections for the S0 port are explicitly excluded in the interface table.
- The existing connection is using all B-channels (channel bundling).
- The existing connection is a leased line. Only a few ISDN providers allow a dial-in connection to be established on the second B-channel in parallel with a permanent connection on the first B-channel.
