Cisco Catalyst 2960 Series, Configuration Manual

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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
Default Setting Feature
Enabled in Cisco IOS software, requires
configuration
12
DHCP server
Enabled
13
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
14
None configured DHCP snooping limit rate
Untrusted DHCP snooping trust
Disabled DHCP snooping VLAN
Enabled DHCP snooping MAC address verification
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
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How to Configure DHCP Features