SPECIFICATION
Hedrick, [RFC 1058] Routing Information Protocol June 1988.

D. Comer and D. Stevens. Internetworking with TCP/IP Volume II 2nd Ed. 1994.

SYNOPSIS
An x-kernel implementation of the standard Internet Routing Information Protocol(RIP). RIP allows routers (hosts with more than one connected network) to periodically exchange routing information. End hosts (hosts with only one connected network) can use RIP to listen to the RIP packets exchanged by routers to keep there routing table up to date.

This RIP implementation is very standard. It differs from Comer's only in that this RIP maintains its own routing table separate from the IP routing table. Whenever a change is made to the RIP routing table RIP does a control operating on IP to change its routing table.

Warning: RIP may take several seconds to start up after rip_initis finished. All test cases that use rip should delay for at least 30 seconds before starting.

REALM
RIP has no top interface. Its bottom interface is ASYNC.

PARTICIPANTS
RIP does not support open or openenable.

CONTROL OPERATIONS
RIP does not support control operations.

CONFIGURATION
RIP can be configured only on top of UDP in a standard Internet protocol graph. RIP depends upon VNET control operations to determine how many networks the current host is connected to and to tell which network a given packet arrived on. RIP will not work without VNET. Based on the number of networks configured below VNET RIP will configure itself as an router or end-host RIP instance.

AUTHORS
Sean O'Malley (based on Comer's source)