Subject: [dhcwg] Call for discussion: How to solve current option82's problem.

From: "Huanglu" <[email-masked]>
Date: Wed, 21 Oct 2009 15:20:11 +0800

Dear all,

RFC 3046 allows only the first Relay Agent to append Relay Agent Information option.  In some networks, Layer 2 Relay Agents and Layer 3 Relay Agents are deployed but only Layer 2 Relay Agent appends the Relay Agent Information option.  The document (http://tools.ietf.org/html/draft-huang-dhc-relay-ps) describes two pretty common network scenarios that uses Layer 2 and Layer 3 Relay Agents and their unique requirements where either DHCP server or Relay Agent need more information to handle DHCP messages.

In a short word, what we need are:
1. Multiple relay agents can insert their information in the same DHCP message
2. The relay agent information should include Agent ID, Agent address (optional), Downstream interface, Agent level

Now we have two choises to solve the problems:
1. Extend option82's information and allow inserting multiply option82 (for example, http://tools.ietf.org/html/draft-kurapati-dhc-relay-chaining-dhcpv4-01 plus http://www.ietf.org/id/draft-ietf-dhc-relay-id-suboption-07.txt )
--This solution can use some previous work, but we should integrate all of them. And we have to change the deployed relay agents software code of option82.
2. Define a new option which include all of what we need ( We just finished a draft for this: http://tools.ietf.org/html/draft-huang-dhc-multiple-relay-agents-option )
--This solution can solve the problem once and for all. And we can use option82 as before. Of course we still have to change the deployed relay agents software code to support the new option. 

Please let us know your comments on the solutions or you can give some new suggestions.

Thanks

Best Regards!
Lu Huang