Hi Keith, On Wed, 2002-11-27 at 00:21, Keith Moore wrote: > > I suppose basically I'm considering internal to be any time one > > organisation chooses to make its GUPI address space routes available to > > another, and accept the other organisation's GUPI address space routes. > > The organisation knows who it is talking to and vice versa (I'm not > > talking about a trust relationship here though - just the conscious > > decision to interconnect to each other's networks and the trading of > > GUPI routes). > > Okay, it just seems like an odd use of the word "internal" to me. > (I'm tempted to quote Lewis Carroll here but I won't. :) >
It probably is, although the terms internal and external in this context remind me of the way "internal" and "external" are used to describe routes in an IGP. An IGP prefers its internal routes over equivalent external routes because it discovered them itself, verses just being told the external route and an arbitrary metric. Here is an alternative analogy - you can choose your friends (organisations you communicate with by directly connecting with (logically or physically) and trading GUPI /48 prefixes), you can't choose you relatives (everybody else on the public Internet, for which you use global addresses). I'm open to alternative describing words - I initially thought about on-site (internal) and off-site (external), but wanted to avoid the word "site" - people's default understanding of it is geographical, I didn't want to imply any sort of geographical scope for my "internal" communications. > > > Another difference is that I see little reason for a network to support > > > both GUPIs and globals - if a network has globals then it is probably > > > better off without GUPIs. Yes, GUPIs might be more stable than globals, > > > but this is not necessarily the case - the opposite could also be true. > > > > > > > Other than internal links failing, causing destination unreachables, > > timeouts etc, what cases would there be where globals are more stable > > that GUPIs ? > > When the site network is renumbered/reorganized more often than the > site's ISP changes the global prefix assigned to the site. People > seem to assume that ISPs will want to change prefixes every week > while the site will wisely manage its address space and never need > to reassign suffixes, but it ain't necessarily so. I've certainly > seen internal renumbering required because of poor address space management > within a site. I agree - while I've known (and been thankful) that a /48 gives you 65K subnets, its only when I read this did it really occur to me that some organisations will need to use aggregation within their /48 - /64 address space to shrink their route tables. Pretty obvious really, I just got a bit blinded by having so many subnets to play with :-) Regards, Mark. -------------------------------------------------------------------- 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] --------------------------------------------------------------------
