arp snooping enable

Function

The arp snooping enable command enables ARP snooping.

The undo arp snooping enable command disables ARP snooping.

By default, ARP snooping is disabled on the device.

Format

arp snooping enable

undo arp snooping enable

Parameters

None

Views

System view, VLAN view, Ethernet interface view, GE interface view, XGE interface view, 25GE interface view, MultiGE interface view, 40GE interface view, 100GE interface view, Eth-Trunk interface view, port group view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

During video network O&M, the NMS needs to obtain the IP addresses and MAC addresses of NEs to draw a network topology for subsequent O&M. For LLDP-incapable NEs, you can configure the ARP snooping function on the access switch. This function enables the device to obtain the IP addresses and MAC addresses of NEs from the ARP packets sent from the NEs, and generate ARP snooping entries.

After ARP snooping is enabled, the device sends the received ARP packets to the CPU. The CPU analyzes the ARP packets to obtain the source IP address, source MAC address, VLAN ID, and inbound interface of the packets, and creates an ARP snooping entry to record user information.

After an ARP snooping entry is created, it ages after 900 seconds by default. An ARP snooping entry is created based on the source IP address and VLAN information of an ARP packet. If no ARP snooping entry matches the source IP address and VLAN information of a received ARP packet, the device creates a new ARP snooping entry. If the source IP address and VLAN information of a received ARP packet are the same as those in an existing ARP snooping entry, the device updates the MAC address and interface information in the entry and resets the aging timer.

Precautions

You must enable ARP snooping in the system view, and then enable ARP snooping in a VLAN or on an interface.

Example

# Enable ARP snooping on GE0/0/1.

<HUAWEI> system-view
[HUAWEI] arp snooping enable
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] arp snooping enable

# Enable ARP snooping in VLAN 100.

<HUAWEI> system-view
[HUAWEI] arp snooping enable
[HUAWEI] vlan 100
[HUAWEI-vlan100] arp snooping enable