Enabling periodic refresh of dynamic relay entries
About enabling periodic refresh of dynamic relay entries
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 the IP address of a relay entry to periodically send a DHCP-REQUEST message to the DHCP server.
The relay agent maintains the relay entries depending on what it receives from the DHCP server:
If the server returns a DHCP-ACK message or does not return any message within an interval, the DHCP relay agent removes the relay entry. In addition, upon receiving the DHCP-ACK message, the relay agent sends a DHCP-RELEASE message to release the IP address.
If the server returns a DHCP-NAK message, the relay agent keeps the relay entry.
Procedure
Enter system view.
system-view
Enable periodic refresh of dynamic relay entries.
dhcp relay client-information refresh enable
By default, periodic refresh of dynamic relay entries is enabled.
(Optional.) Set the refresh interval.
dhcp relay client-information refresh [ auto | interval interval ]
By default, the refresh interval is auto, which is calculated based on the number of total relay entries.