RIP

Reference Manual

HOW TO use the Routing Information Protocol: RIP

The Routing Information Protocol is a simple Interior Gateway protocol that is used to propagate routing information within local area networks. It can be quite useful on private LANs that consist of multiple networks interconnected by routers. For example, consider a router which connects to network 192.168.1.0 on one interface and to network 192.168.2.0 on another interface. If the router has a default route pointing to a gateway on network 192.168.1.0 then a machine on the 192.168.2.0 network will be able to reach that gateway. However, the gateway will not be able to reach the 192.168.2.0 network, unless it is told that the 192.168.2.0 network lies behind the 192.168.1.0 network. This is done by specifying a network-specific route within the gateway.

The RIP protocol can be used by the router to advertise the networks it can reach. The gateway will then learn of the 192.168.2.0 network and that it lies behind the 192.168.1.0 network.

NAT32 fully supports RIP, and the listener is enabled by issuing the command:

startd rip

NAT32 will then accept RIP updates from other machines and update its routing table accordingly.

If NAT32 is to actively propagate routes, the listener and an announcer can be started with command:

startd rip 1

The announcer will only advertise routes on interfaces that have been enabled with the command:

setrip ifn on

Argument 'ifn' is the interface number and the value 'p' can be used to specify the Primary (i.e. the Internet connected) interface, and the value 's' can be used to specify the Secondary (i.e. the private) interface.

RIP updates are normally broadcast every 30 seconds on UDP port 520. To force NAT32 to broadcast a RIP update without delay, enter the command:

rip

To immediately announce routes over a specific interface, enter the command:

rips ifn

To turn off RIP, enter the command:

rip kill from the Console.

Because the NAT32 RIP implementation can be configured to not propagate or accept RIP updates on a specific interface, it is quite safe to use in an Internet Connection Sharing environment.

SEE ALSO

Internet Connection Sharing Modules, Multiple Subnets, How-To Index