I like the rule below as it seems to nicely separate responsibilities. Will it be self evident when (others) are applying the specific mechanisms mentioned that the flow label (being unprotected) should not be used in a way that circumvents normal routing rules or security policies?
Craig. -----Original Message----- From: Margaret Wasserman [mailto:[EMAIL PROTECTED]] Sent: December 20, 2001 11:50 AM To: [EMAIL PROTECTED] Subject: Re: draft-rajahalme-ipv6-flow-label-00.txt Hi All, I am wondering why we should specify the use of the flow label as part of the base IPv6 specifications at all. Why do we need these rules as part of IPv6? The flow label does not, by itself, provide any useful information that a router can use to classify a flow and/or optimize packet handling. In fact, without knowledge of a specific signalling mechanism or flow-establishment mechanism, the router can't use the flow label for anything at all. For example, a router cannot use a flow label for QoS queuing or to optimize hop-by-hop header processing, unless the router is aware of the signalling/ flow-establishment mechanism in use, since it will not know the flow lifetime. Any rules governing how the flow label is chosen, modified, authenticated and/or interpreted will be specific to the signalling/flow-establishment mechanism in use. And, all of the nodes/routers that are utilizing one of these mechanisms will be aware of the mechanism. So why not specify the semantics/use/etc. of the flow label as part of the signalling/flow establishment protocols? The IPv6 specifications could merely include the current rule: "Hosts or routers that do not support the functions of the Flow Label field are required to set the field to zero when originating a packet, pass the field on unchanged when forwarding a packet, and ignore the field when receiving a packet." [from RFC 2460]. This rule should properly protect the flow label, so that signalling/flow-establishment mechanisms can use the flow label, as needed by the specific mechanism. Margaret -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
