Rip Updates, V1 And V2 - HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual

Secure router
Hide thumbs Also See for ProCurve Secure Router 7203 dl:
Table of Contents

Advertisement

When a router receives a route that it does not know from a neighbor, it adds
it to its routing table. The source of the update becomes the next-hop address
for the destination, and the metric is the advertised metric plus one. That is,
because the router is one hop from the source of the update, the router is also
one more hop from the destination. After the router adds the route to its table,
it can advertise this route itself, with the incremented metric.
The ProCurve Secure Router sends out all RIP routes on all RIP interfaces.
Before sending a RIP route, however, the ProCurve Secure Router examines
the next-hop address, or the source of the route. If the router is sending an
update to a source for a particular route, it sends a poison reverse instead
of the normal route. A poison reverse is a route with a metric of 16 (which
is infinity for RIP). The poison reverse distinguishes a legitimate redundant
route from a route that the local router has received from the neighbor.
Essentially, the poison reverse informs the neighbor that it cannot reach the
network in question through the local router. This mechanism is called split
horizon with poison reverse, and the rationale for it is explained in "Speeding
Convergence: Split Horizon, Poison Reverse, and Triggered Updates" on
page 13-15.
Routers change entries in their routing tables for several reasons:
The neighbor listed as the next-hop address changes the metric for the
route. The router then changes the metric for the route in its own table to
the new metric plus one.
A different neighbor advertises a route with a lower metric. The router
changes the route to list this neighbor as the next-hop address and enters
the new metric.
The router does not receive information about the route for the entire
length of the invalid interval. The router marks the route for deletion. It
sends out poison updates for the route for two update cycles before
removing the route entirely from its routing table.

RIP Updates, v1 and v2

RIP update packets contain different information, depending on whether the
RIP version is 1 or 2.
A RIP v1 packet includes:
a command field—indicating whether the packet is a request or a reply
a version field (set at 1)
IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring RIP
13-13

Advertisement

Table of Contents
loading

This manual is also suitable for:

Procurve secure router 7102 dl

Table of Contents