> (1) If there are multiple addresses per node, then the application > needs to somehow iterate through the various src/dest combos until it > finds one that works. If multiple ones would work, how does it choose > the best combo?
iteration is often too slow, especially if there are lots of address pairs and the default rules don't work well. > (2) If there are filters in place, then addresses that work from one > node attached at one point may not work from a different node or a > different location. > > If we agree to remove filters and have one address per node, then we > can continue to write simplistic apps. If not, then applications need > to use techniques that allow them to cope with these issues. > > Notice that if an application only creates connections using a single > pair of endpoints then (assuming no mobility) it only has to deal with > issue #1. Issue #2 only comes into play when applications forward IP > address to other applications and expect them to keep working. > Sending DNS addresses instead may be a solution for some applications. whether this works depends on both DNS configuration and the app. it would be far better if the apps had a way of doing referrals that didn't suffer the unreliability and delays of DNS and which wasn't so sensitive to DNS (mis-) configuration. > This discussion is only relevant to 'local' addresses in as much as > local addresses are one class of filtered address. As soon as you > introduce filters you MUST consider #2, regardless of your address > 'scope'. local addresses are also ambiguous, which further complicates things. > Network ambiguity is largely irrelevant - the connection succeeds or > it doesn't (remember that most nodes have a unique interface id). timeouts take a long time, and the probability that an ambiguous address is invalid is high. Keith -------------------------------------------------------------------- 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] --------------------------------------------------------------------
