Enabling the DHCP relay agent to record relay entries
About enabling the DHCP relay agent to record relay entries
Perform this task to enable the DHCP relay agent to automatically record clients' IP-to-MAC bindings (relay entries) after they obtain IP addresses through DHCP.
Some security features use the relay entries to check incoming packets and block packets that do not match any entry. In this way, illegal hosts are not able to access external networks through the relay agent. Examples of the security features are ARP address check, authorized ARP, and IP source guard.
Rustications and guidelines
The DHCP relay agent does not record IP-to-MAC bindings for DHCP clients running on synchronous/asynchronous serial interfaces.
Procedure
Enter system view.
system-view
Enable the relay agent to record relay entries.
dhcp relay client-information record
By default, the relay agent does not record relay entries.