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 in this process:
- Rejected routes with the '0.0.0.0' router setting.
- Routes referring to other routers in the local network.
- Routes linking individual computers to the LAN by proxy ARP.
Although the entries in the static routing table are set manually, this information changes according to the connection status of the router and so do the RIP packets transmitted.
- If the router has established a connection to a remote station, it propagates all the networks which can be reached via this route in the RIPs with the distance '1'. Other routers in the LAN are thus informed by these means that a connection to the remote station has been established on this router which they can use. The establishment of additional connections by routers with dial-up connections can be prevented, thus reducing connection costs.
- If this router cannot establish a further connection to another remote
station, all other routes are propagated with the distance '16' in the
RIP. The '16' stands for “This route is not available at the moment”.
A router may be prevented from establishing a connection in addition
to the present one may be due to one of the following causes:
- Another connection has already been established on all the other channels (also via the LANCAPI).
- Y connections for the S0 port have been explicitly excluded in the interface table.
- The existing connection is using all B channels (channel bundling).
- The existing connection is a leased-line connection. Only a few ISDN providers enable a dial-up connection to be established on the second B channel in addition to a permanent connection on the first B channel.