Can someone explain the rational for why RFC 4007 mandates the scope zone index before the prefix in the textual representation?
It appears to be the reverse of what I would expect. A prefix is assocaited with the IP address itself (in6_addr), while the scope zone index is associated with the socket address (sockaddr_in6), therefore it would appear to make more sense if the prefix were bound more closely to the IP address than the scope zone index. To illustrate: Suppose we have a function in6_addr_pton which converts a textual representation of an IP address to an in6_addr. I would expect such a function to accept prefix notation, but not scope zone index notation (since scope_id is stored in a sockaddr_in6 and not in an in6_addr). Likewise, assuming a function, sockaddr_in6_pton, which converts a textual representation of a transport address (i.e. IP + port), I would expect it to accept both prefix (passed with IP address to in6_addr_pton) and scope zone index (as well as port) notation. /* Convert text in the form "ip6 ['/' prefix]" to in6_addr */ int in6_addr_pton(const char* str, in6_addr* addr) {} /* Convert text in the form "'[' ip6 ['/' prefix] ['%' scope] ']' ':' port" to sockaddr_in6 */ int sockaddr_in6_pton(const char* str, socketaddr_in6* sa) { call in6_addr_pton() with substring "ip6 ['/' prefix]" to extract IP address to sa.sin6_addr extract scope ID (if present) to sa.sin6_scope_id extract port to sa.sin6_port } Section 11.7 says its important to put the scope zone index first for parsing by name-to-address functions and references a document that I was unable to find. I understand the "name-to-address functions" to mean getaddrinfo. However I'm not clear why getaddrinfo should care that scope zone index appeared first assuming the substring "ip6 ['/' prefix]" were handled by a function similar in6_addr_pton above. --Stephen -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Haberman Sent: Tuesday, April 05, 2005 7:00 AM To: Joe Abley Cc: grow@lists.uoregon.edu; ipv6@ietf.org; Pekka Savola Subject: Re: grow: ipv6 anycast Hi Joe, On Apr 4, 2005, at 22:12, Joe Abley wrote: > > On 4 Apr 2005, at 08:35, Pekka Savola wrote: > >> This is a timely topic, because IPv6 WG just less than week ago >> forwarded the revision of the addressing architecture to be published >> as Draft Standard. (IPv6 WG is Cc:ed.) >> >> That draft, >> http://www.ietf.org/internet-drafts/draft-ietf-ipv6-addr-arch-v4 >> -02.txt still has the problematic wording wrt anycast addresses. > > Yes, I noticed that. I sent mail to the authors of that draft asking > them for their thoughts on the anycast issue, but I haven't heard > anything back, yet. As a note, the current editor is only intermittently reachable due to personal travel. > > Assuming there is consensus that v6 anycast for host-based services is > a fait accompli, and that further prohibition is unnecessary, it would > seem that adjusting the relevant paragraph in the revised (v4) v6 > addressing spec would be the cleanest way of proceeding. My personal opinion is that the restriction should be lifted. > > However, although I think we had some kind of consensus to that effect > in the grow meeting in Minneapolis, I haven't heard any opinion from > those ipv6-wg folks who don't also participate in grow. Seems like > some kind of hum from the ipv6 floor would be useful to hear (or, if > no hum, active throwing of furniture). > I will pose that question to the group and report back. Regards, Brian -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------