On Sun, 2005-10-16 at 11:08 -0400, Joe Abley wrote:
Am I mistaken in thinking that if shim6 (or something like it) did exist, that portable address space could be allocated to everyone (maybe with a different allocation policy?) to be used as (shim6) identifiers.
Yes, you're mistaken. The locator identifier is chosen from the host's pool of upper-layer identifiers.
From section 3: "There are a number of options in the choice of an endpoint identity realm, including the use of existing addresses as an identity tokens,
Sorry, maybe I wasn't clear when I said identifier - I meant endpoint identity (ULID) not locator. I had read a portion (most of the first 3 sections) of draft-ietf-shim6- arch-00.txt to try and get the main concepts. Just so I get it straight, as I've read it, there are ULIDs (which I mistakenly called identifiers in my previous posts), and there are locators (which are real routable IP addresses). the use of distinguished (possibly non-routeable) addresses as tokens, or the use of tokens drawn from a different realm (such as use of a fully qualified domain name). Shim6 uses the first of these options, and the endpoint identity for a host is one of the locator addresses that are normally associated with the host. The particular locator address selected to be the endpoint identity (or ULID) is specified in [RFC3484]. Shim6 does not mandate the use of distinguished addresses as identities, although the use non-routeable distinguished addresses in this context is described as an option in this approach." So currently, shim6 will always use a routable IP address (one of the locators) as the ULID, but it seemed to leave the option open for non- routable addresses to be used. Therefore, my conclusion that a portable (but non-routed) address might be used. ..... And now, after reading the rest of the draft, I see that use of non- routable addresses has only been explored at an abstract level. Obviously the null tranform for ULID->locator wouldn't work when establishing a session if the ULID was non-routable. One comment/question and I know this is probably the wrong forum, but in section 4.1 there is a question "What form of token is passed to the IP layer from the upper level protocol element as an identification of the remote session target?". As part of the answer, it says "If the initial identification of the remote host is via a domain name, then this approach assumes that there are a one or more locators held in the DNS." Should that not read that "there are one or more ULIDs held in DNS"? Although in practice, it seems that the set of ULIDs and locators will probably be the same (although not always?) so it probably won't matter much. John