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IP DHCP Snooping Commands
ip dhcp snooping limit rate
ip dhcp snooping limit rate
Cisco 220 Series Smart Plus Switches Command Line Interface Reference Guide Release 1.0.0.x
Default Configuration
The switch drops DHCP packets with option-82 information which are received on
the untrusted ports that might be connected to an edge switch.
Command Mode
Interface Configuration mode
User Guidelines
You may want an edge switch to which a host is connected to insert DHCP option-
82 information at the edge of your network. You may also want to enable the DHCP
security features, such as DHCP snooping, IP source guard, or dynamic ARP
inspection, on an aggregation switch. However, if DHCP snooping is enabled on
the aggregation switch, the switch drops packets with option-82 information that
are received on an untrusted port and does not learn DHCP snooping bindings for
connected devices on a trusted interface.
If the edge switch to which a host is connected inserts option-82 information, and
you want to use DHCP snooping on an aggregation switch, enter the ip dhcp
snooping information option allow-untrusted command on the aggregation switch.
The aggregation switch can learn the bindings for a host even though the
aggregation switch receives DHCP snooping packets on an untrusted port. You
can also enable the DHCP security features on the aggregation switch. The port on
the edge switch to which the aggregation switch is connected must be configured
as a trusted port.
Example
switchxxxxxx(config)# interface fa3
switchxxxxxx(config-if)# ip dhcp snooping information option allow-untrusted
To configure the number of DHCP messages that an interface can receive per
second, use the ip dhcp snooping limit rate Interface Configuration mode
command.
To revert to its default setting, use the no form of this command.
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