Nortel Networks NN47200-503 manual An Introduction to IP Routing Protocols, IP addressing

13

An Introduction to IP Routing Protocols

This chapter provides an introduction to IP routing and IP routing protocols used in the Nortel Ethernet Routing Switch 5500 Series. Subsequent chapters will provide a more detailed description of switch capabilities and configuration procedures.

IP routing

To configure IP routing on the Nortel Ethernet Routing Switch 5500 Series, use virtual local area networks (VLAN) to create virtual router interfaces by assigning an IP address to the VLAN. This section discusses this concept in depth.

For a more detailed description about VLANs and their use, consult Nortel Ethernet Routing Switch 5500 Series Release 5.1 Configuration - VLANs, Spanning Tree, and Link Aggregation.

IP addressing

An IP version 4 (IPv4) address consists of 32 bits expressed in a dotted-decimal format (XXX.XXX.XXX.XXX). The IPv4 address space is divided into classes, with classes A, B, and C reserved for unicast addresses and accounting for 87.5 percent of the 32-bit IP address space. Class D is reserved for multicast addressing. " IP address classifications" (page

13)lists the breakdown of the IP address space by address range and mask.

IP address classifications

Class	Address Range	Mask	Number of	Nodes per
			Networks	Network
A	1.0.0.0 - 127.0.0.0	255.0.0.0	127	16,777,214
Note: Although technically part of Class A addressing, network 127 is reserved
for loopback.
B	128.0.0.0 -	255.255.0.0	16,384	65,534
	191.255.0.0
C	192.0.0.0 -	255.255.255.0	2,097,152	255
	223.255.255.0

Nortel Ethernet Routing Switch 5500 Series

Configuration-IP Routing Protocols

NN47200-503 03.01 Standard

5.127 August 2007

Copyright © 2005-2007, Nortel Networks