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

  1. Enter system view.

    system-view

  2. Enable the relay agent to record relay entries.

    dhcp relay client-information record

    By default, the relay agent does not record relay entries.