Cisco Systems ME3400G2CSA Configuring DHCP Features and IP Source Guard

CHAPTER

18-1

Cisco ME 3400 EthernetAccess Switch SoftwareConfiguration Guide

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Configuring DHCP Features and IP Source Guard

This chapter describes how to configure DHCP snooping and the option-82 data insertion features on the

Cisco ME 3400 Ethernet Access witch. It also describes how to configure t h e IP sour ce g ua rd fea ture ,

which is supported on switches running the metro access and metro IP access images.

Note For complete syntax and usage information for the commands used in this chapter, see the command

reference for this release, and see the “DHCP Commands” section in the Cisco IOS IP Command

Reference, Volume 1 of 3: Addressing and Services, Release 12.2.

This chapter consists of these sections:

•Understanding DHCP Features, page 18-1

•Configuring DHCP Features, page 18-6

•Displaying DHCP Snooping Information, page 18-13

•Understanding IP Source Guard, page 18-13

•Configuring IP Source Guard, page 18-14

•Displaying IP Source Guard Information, page 18-16

DHCP is widely used in LAN environments to dynamically assign host IP addresses from a centralized

server, which significantly reduces the overhead of administration of IP addresses. DHCP also helps

conserve the limited IP address space because IP addresses no longer need to be permanently assigned

to hosts; only those hosts that are connected to the network consume IP addresses.

These sections contain this information:

•DHCP Server, page 18-2

•DHCP Relay Agent, page 18-2

•DHCP Snooping, page 18-2

��Option-82 Data Insertion, page 18-3

•DHCP Snooping Binding Database, page 18-5

For information about the DHCP client, see the “Configuring DHCP” section of the “IP Addressing and

Services” section of the Cisco IOS IP Configuration Guide, Release 12.2.