272
To do…
Use the command…
Remarks
Configure the port as a
trusted port on which ARP
detection does not apply
arp detection trust
Optional
The port is an untrusted port by default.
NOTE:
When configuring this feature, you need to configure ARP detection based on at least static IP source guard
binding entries, DHCP snooping entries, or 802.1X security entries. Otherwise, all ARP packets received from an
ARP untrusted port will be discarded, except the ARP packets with an OUI MAC address as the sender MAC
address when voice VLAN is enabled.
When configuring an IP source guard binding entry, you need to specify the VLAN; otherwise, no ARP packet
will pass the ARP detection based on static IP source guard binding entries.
Configuring ARP detection based on specified objects
With this feature configured, the switch permits the ARP packets received from an ARP trusted port to pass
directly, and checks the ARP packets received from an ARP untrusted port. You can specify objects in the
ARP packets to be detected. The objects involve:
src-mac: Checks whether the sender MAC address of an ARP packet 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 in an ARP packet. Any all-zero, all-one or multicast IP
addresses are considered invalid and the corresponding packets are discarded. With this object
specified, the sender and target IP addresses of ARP replies, and the source IP address of ARP
requests are checked.
Follow these steps to configure ARP detection based on specified objects:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter VLAN view
vlan
vlan-id
—
Enable ARP detection for the
VLAN
arp detection enable
Required
Disabled by default.
Return to system view
quit
—
Specify objects for ARP detection
arp detection validate
{
dst-mac
|
ip
|
src-mac
} *
Required
Not specified by default.
Enter Layer 2 Ethernet port
view/Layer 2 aggregate interface
view
interface
interface-type interface-
number
—
Configure the port as a trusted
port on which ARP detection does
not apply
arp detection trust
Optional
The port is an untrusted port by
default.