![](/images/new-backgrounds/1316947/316947703x1.webp)
9
RIP
RIP is a commonly used IGP. RIP version 1 is described in RFC 1058, and RIP version 2 is described in RFC 1723. IPSRD supports these version, as well as RIPng, which supports IPv6 interfaces.
RIP uses a simple distance vector algorithm called Bellman Ford to calculate routes. In RIP, each destination has a cost or metric value, which is based solely on the number of hops between the calculating firewall and the given destination.
The maximum metric value is 15 hops, which means that RIP is not suited to networks within a diameter greater than 15 firewalls. The advantage of RIP version 2 over RIP version 1 is that it supports
IGRP
IGRP (Interior Gateway Routing Protocol) is a distance vector protocol. IGRP has a number of metrics for each destination. These metrics include link delay, bandwidth, reliability, load, MTU, and hop count. A single composite metric is formed by combining metrics with a particular weight.
Like RIP version 1, IGRP does not fully support
OSPF
OSPF (Open Shortest Path First) is a modern
OSPF allows the AS to be broken up into areas. Areas allow you to increase overall network stability and scalability. At area boundaries, routes can be aggregated to reduce the number of routes each firewall in the AS must know about. If there are multiple paths to a single destination with the same computed metric, OSPF can install them into the forwarding table.
DVMRP
DVMRP (Distance Vector Multicast Routing Protocol) is a multicast routing protocol (RIP, OSPF, and IGRP are unicast routing protocols). Multicasting is typically used for
BGP
BGP (Border Gateway Protocol) is an exterior gateway protocol that is used to exchange network reachability information between
352 | Nokia Network Voyager for IPSO 4.0 Reference Guide |