Filter
Top Products
21-8
Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 21 Configuring DHCP Features and IP Source Guard
Configuring DHCP Snooping
Configuring DHCP Snooping
These sections contain this configuration information:
• Default DHCP Snooping Configuration, page 21-8
• DHCP Snooping Configuration Guidelines, page 21-9
• Configuring the DHCP Server, page 21-10
• Configuring the DHCP Relay Agent, page 21-10
• Specifying the Packet Forwarding Address, page 21-10
• Enabling DHCP Snooping and Option 82, page 21-12
• Enabling DHCP Snooping on Private VLANs, page 21-13
• Enabling the Cisco IOS DHCP Server Database, page 21-14
• Enabling the DHCP Snooping Binding Database Agent, page 21-14
Default DHCP Snooping Configuration
Table 21-1 shows the default DHCP snooping configuration.
Ta ble 21-1 Default DHCP Snooping Configuration
Feature Default Setting
DHCP server Enabled in Cisco IOS software, requires configuration
1
1. The switch responds to DHCP requests only if it is configured as a DHCP server.
DHCP relay agent Enabled
2
2. The switch relays DHCP packets only if the IP address of the DHCP server is configured on the SVI of the DHCP client.
DHCP packet forwarding address None configured
Checking the relay agent information Enabled (invalid messages are dropped)
2
DHCP relay agent forwarding policy Replace the existing relay agent information
2
DHCP snooping enabled globally Disabled
DHCP snooping information option Enabled
DHCP snooping option to accept packets on
untrusted input interfaces
3
3. Use this feature when the switch is an aggregation switch that receives packets with option-82 information from an edge switch.
Disabled
DHCP snooping limit rate None configured
DHCP snooping trust Untrusted
DHCP snooping VLAN Disabled
DHCP snooping MAC address verification Enabled
Cisco IOS DHCP server binding database Enabled in Cisco IOS software, requires configuration.
Note The switch gets network addresses and configuration parameters
only from a device configured as a DHCP server.
DHCP snooping binding database agent Enabled in Cisco IOS software, requires configuration. This feature is
operational only when a destination is configured.