38-20
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter38 Configuring IP Unicast Routing
Configuring RIP
You can now set up parameters for the selected routing protocols as described in these sections:
•Configuring RIP, page38-20
•Configuring OSPF, page38-25
•Configuring EIGRP, page38-36
•Configuring BGP, page38-44
•Configuring Protocol-Independent Features, page38-90 (optional)
Configuring RIP
The Routing Information Protocol (RIP) is an interior gateway protocol (IGP) created for use in small,
homogeneous networks. It is a distance-vector routing protocol that uses broadcast User Datagram
Protocol (UDP) data packets to exchange routing information. The protocol is documented in RFC 1058.
You can find detailed information about RIP in IP Routing Fundamentals, published by Cisco Press.
Note RIP is the only routing protocol supported by the IP base image; other routing protocols require the stack
master to be running the IP services image.
Using RIP, the switch sends routing information updates (advertisements) every 30 seconds. If a router
does not receive an update from another router for 180 seconds or more, it marks the routes served by
that router as unusable. If there is still no update after 240 seconds, the router removes all routing table
entries for the non-updating router.
RIP uses hop counts to rate the value of different routes. The hop count is the number of routers that can
be traversed in a route. A directly connected network has a hop count of zero; a network with a hop count
of 16 is unreachable. This small range (0 to 15) makes RIP unsuitable for large networks.
If the router has a default network path, RIP advertises a route that links the router to the pseudonetwork
0.0.0.0. The 0.0.0.0 network does not exist; it is treated by RIP as a network to implement the default
routing feature. The switch advertises the default network if a default was learned by RIP or if the router
has a gateway of last resort and RIP is configured with a default metric. RIP sends updates to the
interfaces in specified networks. If an interface’s network is not specified, it is not advertised in any
RIP update.
These sections contain this configuration information:
•Default RIP Configuration, page 38-20
•Configuring Basic RIP Parameters, page38-21
•Configuring RIP Authentication, page38-23
•Configuring Summary Addresses and Split Horizon, page38-23

Default RIP Configuration

Table38-4 shows the default RIP configuration.