User guide

A-26 Cisco 2500 Series Access Server User Guide

Desktop Protocols

Figure A-11 IP Subnetting Plan

IP Node Numbering

IP uses the bits to the right of the subnet mask to uniquely number each node on the

network. These addresses are conﬁgured manually by the system administrator. Access

servers and routers are also nodes, and require unique node addresses. In Figure A-11, the

fourth octet is used to number the nodes on a subnet, which permits up to 254 nodes on each

subnet (0 and 255 are reserved numbers).

IP ARP requires no special conﬁguration, and will automatically perform Layer 2 address

resolution for IP. Enter the command show arp to check the ARP table on the access server.

IP Routing Protocols

There are several routing protocol options for IP. Network designers should select which

routing protocol to use, taking into consideration such factors as interoperability,

convergence, performance, support of variable length subnet masks (VLSMs), and protocol

overhead.

Router A

FDDI

Token

Ring

Router B

Router C

Router D

172.16.10.0

172.16.30.0

172.16.20.0

172.16.1.0

172.16.2.0

172.16.40.0

H3795