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Configuring ARP restricted forwarding
ARP restricted forwarding controls the forwarding of ARP packets that are received on untrusted ports
and have passed ARP detection in the following cases:
•
If the packets are ARP requests, they are forwarded through the trusted ports.
•
If the packets are ARP responses, they are forwarded according to their destination MAC address.
If no match is found in the MAC address table, they are forwarded through the trusted ports.
Before performing the following steps, make sure that you have configured the
arp detection enable
command.
To enable ARP restricted forwarding:
To do…
Use the command…
Remarks
1.
Enter system view.
system-view
—
2.
Enter VLAN view.
vlan
vlan-id
—
3.
Enable ARP restricted
forwarding.
arp restricted-forwarding enable
Required
Disabled by default
Displaying and maintaining ARP detection
To do…
Use the command…
Remarks
Display the VLANs enabled
with ARP detection
display arp detection
[
|
{
begin
|
exclude
|
include
}
regular-expression
]
Available in any view
Display the ARP detection
statistics
display arp detection statistics
[
interface
interface-type interface-number
] [
|
{
begin
|
exclude
|
include
}
regular-expression
]
Available in any view
Clear the ARP detection
statistics
reset arp detection statistics
[
interface
interface-
type interface-number
]
Available in user view
ARP detection configuration example 1
Network requirements
As shown in
, configure Switch A as a DHCP server and Switch B to support 802.1X. Enable
ARP detection for VLAN 10 to allow only packets from valid clients to pass. Configure Host A and Host
B as local 802.1X access users.