Avaya Media Gateway G250, Administration Manual

Page: 531 / 840

Configuring RIP
Issue 5 June 2008 531
RIP is a distance vector protocol. The router decides which path to use on distance or the
number of intermediate hops. In order for this protocol to work correctly, all the routers, and
possibly the nodes, need to gather information on how to reach each destination in the Internet.
However the very simplicity of RIP has a disadvantage. This protocol does not take into account
network bandwidth, physical cost, and data priority. The Avaya G250/G350 Media Gateway
supports two versions of RIP:
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RIPv1
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RIPv2
RIPv1
RIPv1 is the original version of the RIP protocol. The RIPv1 protocol imposes some limitations
on the network design with regard to subnetting. When operating RIPv1, you must not configure
variable length subnetwork masks (VLMS). Each IP network must have a single mask, implying
that all subnetworks in a given IP network are of the same size. Also, when operating RIPv1,
you must not configure supernets. RIPv1 is defined in RFC 1058.
RIPv2
RIPv2 is a newer version of the RIP routing protocol. RIPv2 solves some of the problems
associated with RIPv1. The most important change in RIPv2 is the addition of a
subnetwork
mask field which allows RIPv2 to support variable length subnetworks. RIPv2 also includes an
authentication mechanism similar to the one used in OSPF. RIPv2 is defined in RFC 2453.
Table 133 summarizes the differences between RIPv1 and RIPv2.
Preventing routing loops in RIP
You can use the following features in RIP to help avoid routing loops:
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Split-horizon
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Poison-reverse
Table 133: RIPv1 vs. RIPv2
RIPv1 RIPv2
Broadcast addressing Multicast addressing
Timer-based – updated every 30 seconds Timer-based – updated every 30 seconds
Fixed subnetwork masks VLSM support – subnet information transmitted
No security Security (authentication)
No provision for external protocols Provision for EGP/BGP (Route tag)