Subject: Re: Setting ipv6 default router without getting a MAC-based ipv6 addr
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-net
Date: 02/26/2000 04:17:22
>> So I have to either (a) have outgoing connections sometimes coming
>> from addresses not in the DNS or (b) change my reverse DNS when I
>> switch network cards?
>> [...]  I don't consider either of those acceptable.

> this is why we need dynamic DNS.  really.

Dynamic DNS just papers over the problem.  Why should the DNS even have
occasion to care when I change network cards?  In IPv4, this is what
ARP was all about (at least for Ethernets; analogous remarks apply for
other media).

> or, we may be able to use ICMPv6 node information query (ping6 -w)
> for reverse lookup if we can assume gethostname(3) contains FQDN.

This assumes that the host is up at the time the lookup is occurring,
and that it's reachable from the DNS server in question.

> seriously, there has to be some spec/document/whatever that describes
> the relationship between:
> - [DHCP-style roamers]
> - [fixed-address roamers]
> - dynamic DNS
> they cover the same topic from different aspect/goal/constraint.

To an extent, yes.

> I believe this problem is is not just for IPv6, it just made it
> visible.

Well, if providing less of a solution for it that IPv4 did counts as
"just ma[king] it visible", perhaps.  With IPv4, I can shut down a
machine on my house LAN and bring it up again with a different MAC
address (change network cards, or move the disk to another machine, or
whatever), and the only difference will be that the ARP caches will
look slightly different.  I don't have to bash the DNS, I don't have to
frob the router, I don't have to retrain my fingers (which know the
addresses of my house machines fairly well), nobody off-segment can
even *tell*, never mind *care* all Just Works.  It sounds as
though this is not true under IPv6, in which case I can't see it as a
step any direction but backwards.

					der Mouse

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