Understanding Dhcp Features - Cisco Catalyst 3560-X Software Configuration Manual

Configuring DHCP Features and IP Source Guard
This chapter describes how to configure DHCP snooping and option-82 data insertion, and the DHCP
server port-based address allocation features on the Catalyst 3750-X or 3560-X switch. It also describes
how to configure the IP source guard feature.Unless otherwise noted, the term switch refers to a
Catalyst 3750-X or 3560-X standalone switch and to a Catalyst 3750-X switch stack.
For complete syntax and usage information for the commands used in this chapter, see the command
Note
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 12.4.
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Understanding DHCP Features

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:
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OL-25303-03
Understanding DHCP Features, page 1-1
Configuring DHCP Features, page 1-8
Displaying DHCP Snooping Information, page 1-16
Understanding IP Source Guard, page 1-16
Configuring IP Source Guard, page 1-18
Displaying IP Source Guard Information, page 1-26
Understanding DHCP Server Port-Based Address Allocation, page 1-26
Configuring DHCP Server Port-Based Address Allocation, page 1-27
Displaying DHCP Server Port-Based Address Allocation, page 1-29
DHCP Server, page 1-2
DHCP Relay Agent, page 1-2
DHCP Snooping, page 1-2
Option-82 Data Insertion, page 1-3
DHCP Snooping and Switch Stacks, page 1-7
C H A P T E R
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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