421
If a match is found, the ARP packet is considered valid and is forwarded. If no match is found, the
ARP packet is considered invalid and is discarded.
Static IP source guard bindings are created by using the ip source binding command. For more
information, see "Configuring IP source guard."
DHCP snooping entries are automatically generated by DHCP snooping. For more information, see
Layer 3—IP Services Configuration Guide.
Configuration guidelines
When you configure user validity check, follow these guidelines:
• Make sure at least one among static IP source guard bindings, and DHCP snooping entries is
configured for user validity check. Otherwise, ARP packets received from ARP untrusted ports
are discarded.
• You must specify a VLAN for an IP source guard binding. Otherwise, no ARP packets can
match the IP source guard binding.
Configuration procedure
To configure user validity check:
1. Enter system view.
system-view
N/A
2. Enter VLAN view.
vlan
vlan-id N/A
3. Enable ARP attack detection.
arp detection enable
By default, ARP attack detection is
disabled.
4. Return to system view.
quit
N/A
5. Enter Layer 2 Ethernet
interface view or Layer 2
aggregate interface view.
interface
interface-type
interface-number
N/A
6. (Optional.)
interface as a trusted interface
excluded
detection.
arp detection trust
By default, an interface is untrusted.
Configuring ARP packet validity check
Enable validity check for ARP packets received on untrusted ports and specify the following objects
to be checked:
• src-mac—Checks whether the sender MAC address in the message body is identical to the
source MAC address in the Ethernet header. If they are identical, the packet is forwarded.
Otherwise, the packet is discarded.
• dst-mac—Checks the target MAC address of ARP replies. If the target MAC address is
all-zero, all-one, or inconsistent with the destination MAC address in the Ethernet header, the
packet is considered invalid and discarded.
• ip—Checks the sender and target IP addresses of ARP replies, and the sender IP address of
ARP requests. all-one, or multicast IP addresses are considered invalid and the corresponding
packets are discarded.
To configure ARP packet validity check:
1. Enter system view.
system-view
N/A