Enabling The Arp Entry Check; Arp Configuration Example; Configuring Gratuitous Arp; Introduction To Gratuitous Arp - 3Com 4210G Series Configuration Manual

Enabling the ARP Entry Check

The ARP entry check function disables the device from learning multicast MAC addresses. With the
ARP entry check enabled, the device cannot learn any ARP entry with a multicast MAC address, and
configuring such a static ARP entry is not allowed; otherwise, the system displays error messages.
After the ARP entry check is disabled, the device can learn the ARP entry with a multicast MAC
address, and you can also configure such a static ARP entry on the device.
Follow these steps to enable the ARP entry check:
To do...
Enter system view
Enable the ARP entry check

ARP Configuration Example

Network requirements
Enable the ARP entry check.
Set the aging time for dynamic ARP entries to 10 minutes.
Set the maximum number of dynamic ARP entries that VLAN-interface 10 can learn to 1,000.
Add a static ARP entry, with the IP address being 192.168.1.1/24, the MAC address being
000f-e201-0000, and the outbound interface being GigabitEthernet 1/0/1 of VLAN 10.
Configuration procedure
<Sysname> system-view
[Sysname] arp check enable
[Sysname] arp timer aging 10
[Sysname] vlan 10
[Sysname-vlan10] quit
[Sysname] interface gigabitethernet 1/0/1
[Sysname-GigabitEthernet1/0/1] port access vlan 10
[Sysname-GigabitEthernet1/0/1] quit
[Sysname] interface vlan-interface 10
[Sysname-vlan-interface10] arp max-learning-num 1000
[Sysname-vlan-interface10] quit
[Sysname] arp static 192.168.1.1 000f-e201-0000 10 gigabitethernet 1/0/1

Configuring Gratuitous ARP

Introduction to Gratuitous ARP

A gratuitous ARP packet is a special ARP packet, in which the sender IP address and the target IP
address are both the IP address of the sender, the sender MAC address is the MAC address of the
sender, and the target MAC address is the broadcast address ff:ff:ff:ff:ff:ff.
A device implements the following functions by sending gratuitous ARP packets:
Use the command...
system-view
arp check enable
2-5
Remarks
—
Optional
By default, the device is disabled from
learning multicast MAC addresses.