HP 445946-001 - Manual (Page 115)

Routing Information Protocol
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RIPv1
RIP version 1 use broadcast User Datagram Protocol (UDP) data packets for the regular routing updates.
The main disadvantage is that the routing updates do not carry subnet mask information. Hence, the
router cannot determine whether the route is a subnet route or a host route. It is of limited usage after the
introduction of RIPv2. For more information about RIPv1 and RIPv2, refer to RFC 1058 and RFC 2453.
RIPv2
RIPv2 is the most popular and preferred configuration for most networks. RIPv2 expands the amount of
useful information carried in RIP messages and provides a measure of security. For a detailed explanation
of RIPv2, refer to RFC 1723 and RFC 2453.
RIPv2 improves efficiency by using multicast UDP (address 224.0.0.9) data packets for regular routing
updates. Subnet mask information is provided in the routing updates. A security option is added for
authenticating routing updates, by using a shared password. HP 10GbE switch software supports using
clear password for RIPv2.
RIPv2 in RIPv1 compatibility mode
HP 10GbE switch software allows you to configure RIPv2 in RIPv1compatibility mode, for using both RIPv2
and RIPv1 routers within a network. In this mode, the regular routing updates use broadcast UDP data
packet to allow RIPv1 routers to receive those packets. With RIPv1 routers as recipients, the routing
updates have to carry natural or host mask. Hence, it is not a recommended configuration for most
network topologies.
NOTE: When using both RIPv1 and RIPv2 within a network, use a single subnet mask throughout
the network.
RIP Features
HP 10GbE switch software provides the following features to support RIPv1 and RIPv2:
Poison
Simple split horizon in RIP scheme omits routes learned from one neighbor in updates sent to that
neighbor. That is the most common configuration used in RIP that is setting this Poison to
disable
. Split
horizon with poisoned reverse includes such routes in updates, but sets their metrics to 16. The
disadvantage of using this feature is the increase of size in the routing updates.
Triggered updates
Triggered updates are an attempt to speed up convergence. When Triggered Updates is enabled
(
/cfg/l3/rip/if x/trigg ena
), whenever a router changes the metric for a route, it sends update
messages almost immediately, without waiting for the regular update interval. It is recommended to
enable Triggered Updates.