The dhcp option-82 ignore-hostname-match command configures a DHCP relay agent to ignore the host name matching check when parsing the Option 82 field.
The undo dhcp option-82 ignore-hostname-match command restores the default configuration.
By default, DHCP relay agents check host names when parsing the Option 82 field.
Usage Scenario
In DHCP relay scenarios, if Dot1q or QinQ VLAN tag termination sub-interfaces are configured for user access and the packets exchanged between a client and a server are transmitted through different upstream and downstream paths, a downstream DHCP relay agent does not know the user VLAN information when forwarding packets from the server to the client. In this case, you can configure an upstream DHCP relay agent to insert the Option 82 field carrying user VLAN information to packets. When a downstream DHCP relay agent receives reply packets from the server, the relay agent can parse the Option 82 field to obtain the user VLAN information and forwards the packets to the client. As the Option 82 field carries the host name of the upstream DHCP relay agent, the downstream DHCP relay agent may fail to parse the Option 82 field. To allow the downstream DHCP relay agent to correctly parse user VLAN information in the Option 82 field, run the dhcp option-82 ignore-hostname-match command to allow the downstream DHCP relay agent to ignore the host name matching check.