Configuring Dhcp Features; Default Dhcp Configuration; Dhcp Snooping Configuration Guidelines - Cisco WS-C3560-48PS-S Software Configuration Manual

Chapter 18

Configuring DHCP Features

Configuring DHCP Features
These sections describe how to configure DHCP snooping and option 82 on your switch:
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Default DHCP Configuration

Table 18-1
Table 18-1 Default DHCP Configuration
Feature
DHCP snooping enabled globally
DHCP snooping information option
DHCP snooping limit rate
DHCP snooping trust
DHCP snooping VLAN

DHCP Snooping Configuration Guidelines

These are the configuration guidelines for DHCP snooping.
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78-16156-01
Default DHCP Configuration, page 18-3
DHCP Snooping Configuration Guidelines, page 18-3
Enabling DHCP Snooping and Option 82, page 18-4
shows the default DHCP configuration.
You must globally enable DHCP snooping on the switch.
DHCP snooping is not active until DHCP snooping is enabled on a VLAN.
When you globally enable DHCP snooping on the switch, these Cisco IOS commands are not
available until snooping is disabled. If you enter these commands, the switch returns an error
message, and the configuration is not applied.
– ip dhcp relay information check global configuration command
– ip dhcp relay information policy global configuration command
– ip dhcp relay information trust-all global configuration command
– ip dhcp relay information trusted interface configuration command
Before configuring the DHCP information option on your switch, make sure to configure the device
that is acting as the DHCP server. For example, you must specify the IP addresses that the DHCP
server can assign or exclude or configure DHCP options for devices.
– If your switch is the DHCP server, see the
section for more information.
– If your DHCP server is a Cisco device, refer to the "IP Addressing and Services" section in the
"Configuring DHCP" chapter of the Cisco IOS IP and IP Routing Configuration Guide for
Release 12.1. Otherwise, refer to the documentation that shipped with the server.
Default Setting
Disabled
Enabled
None configured
Untrusted
Disabled
"Configuring the DHCP Server" section on page 4-5
Catalyst 3560 Switch Software Configuration Guide
Configuring DHCP Features
18-3