arp learning multicast disable

Function

The arp learning multicast disable command disables an interface from learning ARP entries with multicast MAC addresses.

The undo arp learning multicast disable command enables an interface to learn ARP entries with multicast MAC addresses.

By default, if a device is globally enabled to learn ARP entries with multicast MAC addresses, this function is enabled on all the interfaces. If a device is globally disabled from learning ARP entries with multicast MAC addresses, this function is disabled on all the interfaces.

Format

arp learning multicast disable

undo arp learning multicast disable

Parameters

None

Views

Ethernet interface view, GE interface view, XGE interface view, 25GE interface view, 40GE interface view, 100GE interface view, MultiGE interface view, Eth-Trunk interface view, VLANIF interface view, VBDIF interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

An IP address may map a multicast MAC address. In this case, a network administrator has to configure a static ARP entry. After a device is enabled to learn ARP entries with multicast MAC addresses, the device can generate dynamic ARP entries. This reduces a network administrator's workload and decreases network operation and maintenance costs.

After a device is globally enabled to learn ARP entries with multicast MAC addresses, all the interfaces will learn ARP entries when receiving ARP packets with the multicast MAC addresses as source MAC addresses. This increases system resource consumption and affects user service running. You can run the arp learning multicast disable command on an interface to disable the interface from learning ARP entries with multicast MAC addresses.

Precautions

After an interface is disabled from learning ARP entries with multicast MAC addresses, the interface directly discards ARP packets with the multicast MAC addresses as source MAC addresses, which may result in service interruption.

In the multicast service scenario, if the mapping between IP addresses and multicast MAC addresses is not specified using the arp static command, do not disable the specified interface from learning ARP entries with multicast MAC addresses to ensure normal running of the multicast service.

After an interface is disabled from learning ARP entries with multicast MAC addresses using the arp learning multicast disable command, you can run the undo arp learning multicast disable or arp learning multicast enable command on the interface to enable it to learn multicast MAC addresses. The differences between the two commands are as follows:

After you run the arp learning multicast enable command, the configuration on the interface takes effect.
After you run the undo arp learning multicast disable command, the global configuration takes effect.

Example

# Disable an interface from learning ARP entries with multicast MAC addresses.

<HUAWEI> system-view
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] arp learning multicast disable