Hi Francis et.al., as I said a couple of days ago in Budapest, I would like to see an explanation and/or review from the routing point of view. Judging from my (limited) knowledge about IPv6, going for a variable length SLA field would either leave us with "wasted" address space (as the network next door would be a different site and thus should have a different NLA field anyway), or we would end up with a variable length network prefix length (much like in the v4 environment), effectively extending the NLA field into the SLA field. Doing so would probably require a cross-check against existing IPv6-aware IGPs. That is where I would like to see input from the routing camp(s). Regards, Wilfried. ______________________________________________________________________ From: Francis Dupont <Francis.Dupont@enst-bretagne.fr> To: itojun@iijlab.net CC: Haisang Wu <hswu@ns.6test.edu.cn>, 6bone@ISI.EDU Subject: Re: About address allocating Date: Sat, 20 May 2000 15:17:57 +0200 In your previous mail you wrote:
hi, I have the following questions about address allocating: I know SLA is /48, and interface ID should be 64 bits, does it mean that the smallest unit when allocating address is /48? In other words, if I allocate a /48 to a large university, could I allocate a /48 to four middle schools, thus each middle school gets an block less than /48, which is /50. Is this plan reasonable?
=> we'd like to get a /48, ISPs would like to give a /64 to us: - /48 seems a bit too large for a default allocation size - /64 is unusable when you need subneting then the current idea, as presented yesterday here in Budapest at the RIPE meeting, is to introduce "small site" which get /56 (on byte boundary, large enough for up to 256 subnetworks or a few levels of hierarchy). Then /56 will become the default allocation size in RIR allocation & assignment document.
I'm not sure if introducing "small sites" is a good thing... when we switch ISP and they force me to switch from /48 to /56, renumber becomes very hard. => the idea is that it is easier for someone which needs a /48 to deal with its ISP than for a common customer to fight in order to get a /48 because /64 is not enough: this is a compromise for common customers (ie you at home, IIJlab is strong enough to get a /x with x <= 48). I believe it is a good compromise... Regards Francis.Dupont@enst-bretagne.fr -------------------------------------------------------------------------------- _________________________________:_____________________________________ Wilfried Woeber : e-mail: Woeber@CC.UniVie.ac.at UniVie Computer Center - ACOnet : Tel: +43 1 4277 - 140 33 Universitaetsstrasse 7 : Fax: +43 1 4277 - 9 140 A-1010 Vienna, Austria, Europe : RIPE-DB: WW144, PGP keyID 0xF0ACB369 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~