dhcp relay address-check enable

Syntax

dhcp relay address-check enable

undo dhcp relay address-check enable

View

Interface view

Default level

2: System level

Parameters

None

Description

Use dhcp relay address-check enable to enable address check on the relay agent.

Use undo dhcp relay address-check enable to disable address check on the relay agent.

By default, the function is disabled.

With this feature enabled, the DHCP relay agent can dynamically record clients’ IP-to-MAC bindings after clients get IP addresses through DHCP. It also supports static bindings. You can manually configure IP-to-MAC bindings on the DHCP relay agent, so that users can access external networks using fixed IP addresses.

Upon receiving an ARP packet, the DHCP relay agent matches the sender’s IP and MAC addresses in the packet against the bindings (both dynamic and static). If no match is found, the DHCP relay agent does not learn the ARP entry. The sending host cannot access external networks via the DHCP relay agent.

This command can be executed only on Layer 3 Ethernet ports and VLAN interfaces.

The dhcp relay address-check enable command only checks IP and MAC addresses of clients.

Examples

# Enable address check on the DHCP relay agent.

<Sysname> system-view
[Sysname] interface vlan-interface 1
[Sysname-Vlan-interface1] dhcp relay address-check enable