arp-proxy inter-sub-vlan-proxy enable

Function

The arp-proxy inter-sub-vlan-proxy enable command enables inter-VLAN proxy ARP or enables proxy ARP on a sub-interface.

The undo arp-proxy inter-sub-vlan-proxy enable command disables inter-VLAN proxy ARP or disables proxy ARP on a sub-interface.

By default, inter-VLAN proxy ARP is disabled.

Only the S5720-EI, S5720-HI, S5720I-SI, S5720S-SI, S5720-SI, S5735-S, S5735S-S, S5735-S-I, S5730-HI, S5730S-EI, S5730-SI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6720S-SI, S6720-SI, S6730-H, S6730S-H, S6730-S, and S6730S-S support the inter-VLAN proxy ARP.

Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support sub-interface.

Format

arp-proxy inter-sub-vlan-proxy enable

undo arp-proxy inter-sub-vlan-proxy enable

Parameters

None

Views

VLANIF interface view, GE sub-interface view, XGE sub-interface view, MultiGE sub-interface view, 25GE sub-interface view, 40GE sub-interface view, 100GE sub-interface view, Eth-Trunk sub-interface view, VE sub-interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

When hosts are located on the same network segment but belong to different VLANs, you can run the arp-proxy inter-sub-vlan-proxy enable command on interfaces to enable inter-VLAN proxy ARP, implementing IP address resolution between the hosts.

When hosts are located on the same network segment but belong to different sub-VLANs, you can enable inter-VLAN proxy ARP on the VLANIF interface in a super VLAN.

If inter-VLAN proxy ARP is enabled on a sub-interface, the users on the sub-interface who belong to the same network segment but different VLANs can communicate with each other.

Precautions

After inter-VLAN proxy ARP is enabled and packets are sent from different VLANs but do not have the corresponding ARP entries, ARP packets are replicated in all VLANs on the involved sub-interface. If a lot of VLANs are configured, a large number of ARP packets need to be replicated, causing heavy burden on the peer device and abnormalities (such as high CPU usage and broadcast suppression) on downstream devices. In addition, the local device may fail to send ARP packets in time due to the replication of a large number of packets, which may lead to ARP learning failures. Therefore, do not configure too many VLANs on an interface.

After inter-VLAN proxy ARP is enabled on a sub-interface or VLANIF interface, whether packets sent by the sub-interface or VLANIF interface carry tags depends on the link type of the corresponding Layer 2 Ethernet interface, regardless of the mode in which the Layer 2 Ethernet interface is added to a VLAN. For example, packets sent from a sub-interface or VLANIF interface on a trunk interface carry VLAN tags.

Example

# Enable inter-VLAN proxy ARP on VLANIF 100.

<HUAWEI> system-view
[HUAWEI] interface vlanif 100
[HUAWEI-Vlanif100] arp-proxy inter-sub-vlan-proxy enable