Setting The Aging Time For Dynamic Arp Entries; Enabling The Arp Entry Check; Configuring Arp Quick Notify - 3Com 4500G Family Configuration Manual

To do...
Set the maximum number of
dynamic ARP entries that an
interface can learn

Setting the Aging Time for Dynamic ARP Entries

To keep pace with the network changes, the ARP table is refreshed. Each dynamic ARP entry in the
ARP table has a limited lifetime rather than is always valid. Dynamic ARP entries that are not refreshed
before expiring are deleted from the ARP table. The lifetime is called the aging time. The aging time is
reset each time the dynamic ARP entry is used within the lifetime. You can adjust the aging time for
dynamic ARP entries according to the actual network condition.
Follow these steps to set the aging time for dynamic ARP entries:
To do...
Enter system view
Set the aging time for dynamic
ARP entries

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

Configuring ARP Quick Notify

As shown in Figure
between its MAC address and outbound interface on the switch. The switch, however, does not update
its ARP table immediately after the outbound interface changes, and hence may fail to communicate
with the laptop.
arp max-learning-num number
Use the command...
system-view
arp timer aging aging-time
Use the command...
system-view
arp check enable
1-3, the laptop frequently roams between AP 1 and AP 2 and affects the mapping
Use the command...
—
Optional
By default, the device is disabled from
learning multicast MAC addresses.
1-5
Remarks
Optional
2048 by default.
Remarks
—
Optional
20 minutes by default.
Remarks