dhcp relay client-information refresh enable

Use dhcp relay client-information refresh enable to enable the DHCP relay agent to periodically refresh dynamic relay entries.

Use undo dhcp relay client-information refresh enable to disable the DHCP relay agent to periodically refresh dynamic relay entries.

Syntax

dhcp relay client-information refresh enable

undo dhcp relay client-information refresh enable

Default

The DHCP relay agent periodically refreshes relay entries.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

A DHCP client unicasts a DHCP-RELEASE message to the DHCP server to release its IP address. The DHCP relay agent conveys the message to the DHCP server and does not remove the IP-to-MAC entry of the client.

With this feature, the DHCP relay agent uses a client's IP address and the relay interface's MAC address to periodically send a DHCP-REQUEST message to the DHCP server.

• If the server returns a DHCP-ACK message or does not return any message within an interval, the DHCP relay agent performs the following operations:

  • Removes the relay entry.

  • Sends a DHCP-RELEASE message to the DHCP server to release the IP address.

• If the server returns a DHCP-NAK message, the relay agent keeps the entry.

With this feature disabled, the DHCP relay agent does not remove relay entries automatically. After a DHCP client releases its IP address, you must use the reset dhcp relay client-information on the relay agent to remove the corresponding relay entry.

Examples

# Disable periodic refresh of relay entries.

<Sysname> system-view
[Sysname] undo dhcp relay client-information refresh enable

Related commands

dhcp relay client-information record

dhcp relay client-information refresh

reset dhcp relay client-information