F.2.3 Specific Issues

RIP Shutdown

An implementation of RIP SHOULD provide for a graceful shutdown using the following steps:

1. Input processing is terminated,

2. Four updates are generated at random intervals of between two and four seconds, These updates contain all routes that were previously announced, but with some metric changes. Routes that were being announced at a metric of infinity should continue to use this metric. Routes that had been announced with a non-infinite metric should be announced with a metric of 15 (infinity - 1).

DISCUSSION

The metric used for the above really ought to be 16 (infinity); setting it to 15 is a kludge to avoid breaking certain old hosts that wiretap the RIP protocol. Such a host will (erroneously) abort a TCP connection if it tries to send a datagram on the connection while the host has no route to the destination (even if the period when the host has no route lasts only a few seconds while RIP chooses an alternate path to the destination).

RIP Split Horizon and Static Routes

Split horizon SHOULD be applied to static routes by default. An implementation SHOULD provide a way to specify, per static route, that split horizon should not be applied to this route.