Huawei Quidway S2700 Series Configuration Manual page 113

Quidway S2700 Series Ethernet Switches
Configuration Guide - Security
l
Issue 01 (2011-07-15)
The system view is displayed.
2. Run:
dhcp snooping alarm threshold threshold
The alarm threshold of the number of globally discarded packets is set.
By default, the global alarm threshold of the number of discarded DHCP messages is
100 pps.
Configuring the packet discarding alarm function on an interface
1. Run:
system-view
The system view is displayed.
2. Run:
interface interface-type interface-number
The interface view is displayed.
3. Run:
dhcp snooping check dhcp-chaddr enable [ alarm dhcp-chaddr [ enable
[ threshold threshold-value ] | threshold threshold-value ] ]
The functions of checking the DHCP request messages refer to the CHADDR field
and DHCP Request packet discarding alarm are enabled on the interface, and the
threshold that triggers the alarm is set.
By default, the S2700 does not check DHCP request messages refer to the CHADDR
field or generate alarms for packet discarded. The alarm threshold for the rate of
discarded DHCP request messages is 100 pps.
4. Run:
dhcp snooping check dhcp-request enable [ alarm dhcp-request [ enable
[ threshold threshold-value ] | threshold threshold-value ] ]
The functions of checking the DHCP request messages and DHCP Request packet
discarded alarm are enabled on the interface, and the threshold that triggers the alarm
is set.
By default, the S2700 does not check DHCP request messages field or generate alarms
for packet discarded. The alarm threshold for the rate of discarded DHCP request
messages is 100 pps.
5. (Optional) Run:
dhcp snooping alarm { dhcp-chaddr | dhcp-reply | dhcp-request } { enable
[ threshold threshold ] | threshold threshold }
The alarm function is enabled for discarding of DHCP messages received from
untrusted interfaces, and the alarm threshold is set.
By default, the packet discarding alarm is disabled, and the threshold that triggers the
alarm on discarded packets is 100.
After dhcp snooping alarm command is configured, the S2700 discards the following
types of packets:
– DHCP Request messages that do not match entries in the DHCP Snooping binding
table
– DHCP Reply messages received by untrusted interfaces
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