Configuring periodic refresh of dynamic client entries
A DHCP client unicasts a DHCP-RELEASE message to the DHCP server to release its IP address. The DHCP relay agent simply conveys the message to the DHCP server and does not remove the IP-to-MAC entry of the client.
When this feature is enabled, the DHCP relay agent uses the IP address of a client and the MAC address of the DHCP relay interface to send a DHCP-REQUEST message to the DHCP server at specified intervals.
If the server returns a DHCP-ACK message or does not return any message within a specific interval, the DHCP relay agent ages out the entry.
If the server returns a DHCP-NAK message, the relay agent keeps the entry.
To configure periodic refresh of dynamic client entries:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enable periodic refresh of dynamic client entries. | dhcp relay security refresh enable | Optional. Enabled by default. |
3. Configure the refresh interval. | dhcp relay security tracker { interval | auto } | Optional. auto by default. (auto interval is calculated by the relay agent according to the number of client entries.) |