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 17: Default DHCP Configuration
Default Setting
Feature
Enabled in Cisco IOS software, requires configuration
DHCP server
Enabled
DHCP relay agent
None configured
DHCP packet forwarding address
Enabled (invalid messages are dropped)
Checking the relay agent information
Replace the existing relay agent information
DHCP relay agent forwarding policy
Disabled
DHCP snooping enabled globally
Enabled
DHCP snooping information option
Disabled
DHCP snooping option to accept packets on untrusted
input interfaces
None configured
DHCP snooping limit rate
Untrusted
DHCP snooping trust
Disabled
DHCP snooping VLAN
Enabled
DHCP snooping MAC address verification
Enabled in Cisco IOS software, requires configuration.
The switch gets network addresses and
configuration parameters only from a device
configured as a DHCP server.
Note
Cisco IOS DHCP server binding database
Catalyst 2960-XR Switch Security Configuration Guide, Cisco IOS Release 15.0(2)EX1
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OL-29434-01
Configuring DHCP
How to Configure DHCP Features