Nokia IPSO 4.0 manual Rip, 352

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 non-classful routes. Classful routes are old-style class A, B, C routes. You should use RIP version 2 instead of RIP version 1 whenever possible.

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 non-classful routing.

OSPF

OSPF (Open Shortest Path First) is a modern link-state routing protocol. It is described in RFC 2328. It fully supports non-classful networks. OSPF has a single, 24-bit metric for each destination. You can configure this metric to any desired value.

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 real-time audio and video when there is a single source of data and multiple receivers. DVMRP uses a hop-based metric and, like RIP, a distance-vector route calculation.

BGP

BGP (Border Gateway Protocol) is an exterior gateway protocol that is used to exchange network reachability information between BGP-speaking systems running in each AS. BGP is unlike interior gateway protocols (IGRP or OSPF), which periodically flood an intra-domain network with all the known routing table entries and build their own reliability. Instead, BGP uses TCP as its underlying transport mechanism and sends update only when necessary.

352 Nokia Network Voyager for IPSO 4.0 Reference Guide