Cisco Catalyst 3560-X Series, Software Configuration Manual

Page: 660 / 1538

1-8
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Configuring DHCP Features and IP Source Guard
Configuring DHCP Features
When a stack merge occurs, all DHCP snooping bindings in the stack master are lost if it is no longer
the stack master. With a stack partition, the existing stack master is unchanged, and the bindings
belonging to the partitioned switches age out. The new master of the partitioned stack begins processing
the new incoming DHCP packets. For more information about switch stacks, see
Chapter 1, “Managing
Switch Stacks.”
Configuring DHCP Features
•
Default DHCP Configuration, page 1-8
• DHCP Snooping Configuration Guidelines, page 1-9
•
Configuring the DHCP Server, page 1-10
• DHCP Server and Switch Stacks, page 1-10
•
Configuring the DHCP Relay Agent, page 1-11
• Specifying the Packet Forwarding Address, page 1-11
•
Enabling DHCP Snooping and Option 82, page 1-12
• Enabling DHCP Snooping on Private VLANs, page 1-14
•
Enabling the Cisco IOS DHCP Server Database, page 1-14
• Enabling the DHCP Snooping Binding Database Agent, page 1-15
Default DHCP Configuration
Table 1-1 Default DHCP Configuration
Feature Default Setting
DHCP server Enabled in Cisco IOS software, requires
configuration
1
DHCP relay agent Enabled
2
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
Disabled
DHCP snooping limit rate None configured
DHCP snooping trust Untrusted
DHCP snooping VLAN Disabled
DHCP snooping MAC address verification Enabled