279
To do…
Use the command…
Remarks
Enable ARP automatic
scanning
arp scan
[
start-ip-address
to
end-ip-address
]
Required
Return to system view
quit
—
Enable fixed ARP
arp fixup
Required
NOTE:
IP addresses already 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 switch supports. As a result, the switch 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
command. To
delete all such static ARP entries, use the
reset arp all
or
reset arp static
command.
Configuring ARP gateway protection
Introduction
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 procedure
Follow these steps to configure ARP gateway protection:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter Layer 2 Ethernet port
view/Layer 2 aggregate interface
view
interface
interface-type interface-
number
—
Enable ARP gateway protection for a
specified gateway
arp filter source
ip-address
Required
Disabled by default.