Customer Service Center

Environment/Versions RFC 5107 - DHCP Server Identifier Override Suboption Answer The explanation in RFC 5107 (DHCP Server Identifier Override Suboption) describes the use case for why this suboption was created. A relay agent (RA) wishing to have a client's RENEW DHCPREQUEST to come through the RA (versus possibly bypassing it by contacting the DHCP server directly) will insert the Server ID Override suboption with its address. This informs the DHCP server that in its replies (DHCPOFFER, DHCPACK) to use in the Server ID option (option 54) the address specified in the Server ID Override suboption. That is, the DHCP server will use the address from the Server ID Override in the DHCP Server Indentifier Here's also what the RFC says:      This DHCP relay agent suboption, Server Identifier Override, allows      the relay agent to tell the DHCP server what value to place into the      Server Identifier option [5]. The RA then passes this Server ID option back to the client. So in subsequent RENEW DHCPREQUESTs, the client will contact the RA thereby allowing the RA to again insert other relevant information (e.g., Circuit ID, Remote ID)