385
Configuration guidelines
Follow these guidelines when you configure ARP automatic scanning and fixed ARP:
•
IP addresses existing in ARP entries are not scanned.
•
ARP automatic scanning may take some time. To stop an ongoing scan, press
Ctrl
+
C
. Dynamic
ARP entries are created based on ARP replies received before the scan is terminated.
•
The static ARP entries changed from dynamic ARP entries have the same attributes as the manually
configured static ARP entries.
•
Use the
arp fixup
command to change the existing dynamic ARP entries into static ARP entries. You
can use this command again to change the dynamic ARP entries learned later into static ARP
entries.
•
The number of static ARP entries changed from dynamic ARP entries is restricted by the number of
static ARP entries that the device supports. As a result, the device may fail to change all dynamic
ARP entries into static ARP entries.
•
To delete a specific static ARP entry changed from a dynamic one, use the
undo arp
ip-address
[
vpn-instance-name
] command. To delete all such static ARP entries, use the
reset arp all
or
reset
arp static
command.
Configuration procedure
To configure ARP automatic scanning and fixed ARP:
Step Command
1.
Enter system view.
system-view
2.
Enter interface view.
interface
interface-type interface-number
3.
Enable ARP automatic scanning.
arp scan
[
start-ip-address
to
end-ip-address
]
4.
Return to system view.
quit
5.
Enable fixed ARP.
arp fixup
Configuring ARP gateway protection
The ARP gateway protection feature, if configured on ports not connected with the gateway, can block
gateway spoofing attacks.
When such a port receives an ARP packet, it checks whether the sender IP address in the packet is
consistent with that of any protected gateway. If yes, it discards the packet. If not, it handles the packet
normally.
Configuration guidelines
Follow these guidelines when you configure ARP gateway protection:
•
You can enable ARP gateway protection for up to eight gateways on a port.
•
Commands
arp filter source
and
arp filter binding
cannot be both configured on a port.