We need to be careful here. In our rush to eliminate the bad effects of the ambiguity present in site-local addresses today, let's not forget that there are some major plusses to existing site-local addresses that are the result of this ambiguity:
1. They're free. 2. They can be (auto)configured without having to co-ordinate with some outside entity. 3. They cannot be externally routed (Some would consider this to be a minus as well). I believe 1 and 2 can be solved (fairly) easily by other means. The big problem is number 3. The ambiguity is essential to preventing them from ever being routed. An IETF edict not to route some new form of non-ambiguous addresses will be ignored by those who wish to route them. This will likely lead to pressure to turn these new addresses into yet-another type of global address with all the associated routing table explosion inherent to non-aggregatable address space. Another way to look at it is that the current ambiguity in site-locals is a means for protecting the global routing space. If we do away with the ambiguity, we need another method for keeping the global routing tables sane. The only class of solution which I think will truly make everyone happy is to come up with an *aggregatable* globally unique address space that still has properties 1 and 2. In other words, some sort of provider-independent global address space. Properties 1 and 2 are much easier when the aggregatable property is not required. The reason we're in the state we are today is because this is a hard problem. --Brian -------------------------------------------------------------------- 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] --------------------------------------------------------------------
