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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
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Chapter 22 Configuring DHCP Features and IP Source Guard
Configuring DHCP Features
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. For more information about switch stacks, see
Configuring DHCP Features
These sections contain this configuration information:
•
Default DHCP Configuration, page 22-8
•
DHCP Snooping Configuration Guidelines, page 22-9
•
Configuring the DHCP Server, page 22-10
•
DHCP Server and Switch Stacks, page 22-10
•
Configuring the DHCP Relay Agent, page 22-11
•
Specifying the Packet Forwarding Address, page 22-11
•
Enabling DHCP Snooping and Option 82, page 22-12
•
Enabling DHCP Snooping on Private VLANs, page 22-14
•
Enabling the Cisco IOS DHCP Server Database, page 22-14
•
Enabling the DHCP Snooping Binding Database Agent, page 22-15
Default DHCP Configuration
shows the default DHCP configuration.
Table 22-1
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)
DHCP relay agent forwarding policy
Replace the existing relay agent information
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