Dhcp Snooping And Switch Stacks - Cisco Catalyst 2960 series Configuration Manual

How to Configure DHCP Features

DHCP Snooping and Switch Stacks

DHCP snooping is managed on the stack master. When a new switch joins the stack, the switch receives the
DHCP snooping configuration from the stack master. When a member leaves the stack, all DHCP snooping
address bindings associated with the switch age out.
All snooping statistics are generated on the stack master. If a new stack master is elected, the statistics counters
reset.
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.
How to Configure DHCP Features
Default DHCP Snooping Configuration
Table 118: Default DHCP Configuration
Feature
DHCP server
DHCP relay agent
DHCP packet forwarding address
Checking the relay agent information
DHCP relay agent forwarding policy
DHCP snooping enabled globally
DHCP snooping information option
DHCP snooping option to accept packets on untrusted
input interfaces
DHCP snooping limit rate
DHCP snooping trust
DHCP snooping VLAN
DHCP snooping MAC address verification
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
1272
14
Default Setting
Enabled in Cisco IOS software, requires
12
configuration
13
Enabled
None configured
Enabled (invalid messages are dropped)
Replace the existing relay agent information
Disabled
Enabled
Disabled
None configured
Untrusted
Disabled
Enabled