Configuring Arp Automatic Scanning And Fixed Arp; Introduction; Configuration Procedure - HP 5120 EI Switch Series Configuration Manual

[SwitchB-GigabitEthernet1/0/2] quit
# Enable the checking of the MAC addresses and IP addresses of ARP packets.
[SwitchB] arp detection validate dst-mac ip src-mac
# Configure port isolation.
[SwitchB] interface GigabitEthernet 1/0/1
[SwitchB-GigabitEthernet1/0/1] port-isolate enable
[SwitchB-GigabitEthernet1/0/1] quit
[SwitchB] interface GigabitEthernet 1/0/2
[SwitchB-GigabitEthernet1/0/2] port-isolate enable
[SwitchB-GigabitEthernet1/0/2] quit
After the preceding configurations are complete, when ARP packets arrive at interfaces GigabitEthernet
1/0/1 and GigabitEthernet 1/0/2, their MAC and IP addresses are checked, and then the packets are
checked against the static IP source guard binding entries and finally DHCP snooping entries. However,
ARP broadcast requests sent from Host A can pass the check on Switch B. Port isolation fails.
# Configure ARP restricted forwarding.
[SwitchB] vlan 10
[SwitchB-vlan10] arp restricted-forwarding enable
[SwitchB-vlan10] quit
Switch B forwards ARP broadcast requests from Host A to Switch A through the trusted port
GigabitEthernet 1/0/3, and thus Host B cannot receive such packets. Port isolation works normally.

Configuring ARP automatic scanning and fixed ARP

Introduction

ARP automatic scanning is usually used together with the fixed ARP feature.
With ARP automatic scanning enabled on an interface, the switch automatically scans neighbors on the
interface, sends ARP requests to the neighbors, obtains their MAC addresses, and creates dynamic ARP
entries.
Fixed ARP allows the switch to change the existing dynamic ARP entries (including those generated
through ARP automatic scanning) into static ARP entries. The fixed ARP feature effectively prevents ARP
entries from being modified by attackers.
NOTE:
HP recommends that you use ARP automatic scanning and fixed ARP in a small-scale network such as
a cybercafé.

Configuration procedure

Follow these steps to configure ARP automatic scanning and fixed ARP:
To do...
Enter system view
Enter interface view
Use the command...
system-view
interface interface-type interface-number
278
Remarks
—
—