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Re: stable addressing

On 16-apr-04, at 16:25, Brian E Carpenter wrote:

Things are different however for class 4. Here, renumbering is not a
realistic option. Even if renumbering the actual network infrastructure
were to be doable, changing the associated filters and related security
setups is too much work to undertake at regular intervals.

I would dispute this. All that changes is the /48 prefix, and the normal
case in IPv6 is to be running with several of those simultaneously on
any large site. Actually the filters and internal routing setup will
need to treat the top 48 bits as don't care bits.

This can only work if the bottom 80 bits aren't random. And today they are, to all intents and purposes. But obviously something like draft-van-beijnum-multi6-cbhi-00.txt could change that.

So it seems to me that
relatively simple operational procedures can deal with prefix changes.

Even if security isn't an issue and there is decent address agility higher up in the stack, changing addresses introduces instability and rendezvous issues.

Nevertheless, I assume that all large enterprises will choose to
use a draft-ietf-ipv6-unique-local-addr-03.txt prefix for internal
traffic and some VPN uses. For external traffic I assume they will use
ISP-delegated prefxes, which is where multi6 comes in.

Aarrgghh, multi-faced DNS. It would be better to automatically map these addresses to PA addresses where desired. This way, all the multiadressing issues are nicely hidden in a layer that really knows how to handle them rather than spread around different applications and transport protocols, some of which will handle this beautifully, and some of which will fail miserably.