Subject: [dhcwg] Need info regarding the case when both option 118 and option 82 sub-option 5 are received by dhcp packet

From: Vivek Dadu <[email-masked]>
Date: Mon, 27 Jan 2014 17:27:04 +0000

Hi
RFC 3527 states that when both option 118 and option 82 sub-option 5 are received by DHCP server in a packet it shall the information contained in the link-selection sub- option(option 82 sub-option 5) MUST be used to control the allocation of an IP address in preference to the information contained in the subnet-selection option(option 118) however RFC 3011 (option 118) says that a DHCP proxy client using option 118 shall put its ip address in the GIADDR field. As a result of which the relay agent will not overwrite giaddr and the response packet will be unicasted to DHCP proxy client. Now RFC 3011 again says that if the server is not supporting option 118 then in the response packet it shall not put option 118 as a result of which the client receiving it shall drop it. So in a way I see this as a misconfigration, can somebody throw light on how this problem can be solved.
Regards
Vivek