If multiple DHCP servers are deployed on the network, the design of a server does not comply with standards, and a DHCP client requests for an IP address, the server does not provide an IP address for the DHCP client but still replies with a DHCP ACK message. Alternatively, when the server sends a DHCP Offer message, the DHCP server identifier (Option 54) carried in the message is not that of the server. As a result, the Option 54 is incorrect in the DHCP Request message. The preceding issues affect the methods in which a DHCP relay agent processes DHCP ACK and DHCP Request messages, so that the DHCP client fails to obtain an IP address. You can perform the following steps to change the methods in which a DHCP relay agent processes DHCP ACK and DHCP Request messages to ensure that DHCP clients can obtain IP addresses.
system-view
undo dhcp relay request server-match enable
By default, a DHCP relay agent checks the DHCP server identifier (Option 54) in a DHCP Request message to be forwarded.
dhcp relay reply forward all enable
By default, a DHCP relay agent forwards only the first received DHCP ACK message.