Configuring dhcp packet rate limit, Displaying and maintaining dhcp snooping, Dhcp option customization configuration example – H3C Technologies H3C S12500-X Series Switches User Manual
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Step Command
Remarks
1.
Enter system view.
system-view N/A
2.
Enter interface view of a layer
2 Ethernet interface or a layer
2 aggregate interface.
interface interface-type
interface-number
N/A
3.
Set the maximum number of
DHCP snooping entries that
the interface can learn.
dhcp snooping max-learning-num
number
By default, the number of DHCP
snooping entries for an interface to
learn is not limited.
Configuring DHCP packet rate limit
Perform this task to configure the maximum rate at which an interface can receive DHCP packets. This
feature discards exceeding DHCP packets to prevent attacks that send large numbers of DHCP packets.
To configure DHCP packet rate limit:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter interface view of a layer 2
Ethernet interface or a layer 2
aggregate interface.
interface interface-type
interface-number
N/A
3.
Configure the maximum rate at
which the interface can receive
DHCP packets.
dhcp snooping rate-limit rate
By default, incoming DHCP
packets are not rate limited.
You can configure this command
only on Layer 2 Ethernet
interfaces and Layer 2 aggregate
interfaces.
If you configure the rate on a
Layer 2 Ethernet interface that is a
member port of a Layer 2
aggregate interface, the Layer 2
Ethernet interface uses the DHCP
packet maximum rate configured
on the Layer 2 aggregate
interface. If the Layer 2 Ethernet
interface leaves the aggregation
group, it uses its own DHCP
packet maximum rate.
Displaying and maintaining DHCP snooping
Execute display commands in any view, and reset commands in user view.
Task Command Remarks
Display DHCP snooping entries.
display dhcp snooping binding [ ip
ip-address [ vlan vlan-id ] ]
Available in any
view.