IPv6 in the enterprise

[Ignatios Souvatzis]

Hi,

On Thu, Apr 21, 2011 at 09:17:46AM +0200, S.P.Zeidler wrote:
> Thus wrote Mikael Abrahamsson (swmike at swm.pp.se):
> 
> > On Thu, 21 Apr 2011, S.P.Zeidler wrote:
> > 
> > >So can I. I've got a resolver that changed hardware three times in
> > >the past 6 months and fixing up the address wherever it appears is
> > >getting old.
> > 
> > Could you please elaborate on what you do when you are "fixing it up"?
> 
> Changing resolv.conf on its clients.
> 
> > I would create a dedicated resolver address (a subnet with the
> > address ::53 being the resolver) and then I would move this address
> > around when the service changes physical hardware, perhaps even
> > having it in multiple places (anycast).
> 
> That is an instance of not using SLAAC, yes.

KAME has some magic to take over the low 64 bit as new interface
identifier. I always wanted to look that up... moment... 

     eui64        (inet6 only) Fill interface index (lowermost 64bit of an
		  IPv6 address) automatically.

I always wanted to check this... moment...

> cat /etc/ifconfig.ex0
inet6 fe80::1:C3
up
media autoselect
!rtsol $int
> reboot
-- time passes --
> ifconfig ex0
ex0: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> mtu 1500
[...]
	address: 00:50:da:34:25:bd
	media: Ethernet autoselect (100baseTX full-duplex)
	status: active
	inet pr.ef.ix.195 netmask 0xffffff80 broadcast 131.220.4.255
	inet6 fe80::1:c3%ex0 prefixlen 64 scopeid 0x1
	inet6 2001:pr:ef:ix::1:c3 prefixlen 64

So no, not only is SLAAC not necessarily bound to the default interface 
identifier derived from some unique hardware token - this feature is also
implemented in at least one OS. This would certainly be useful in the
resolver-gets-new-hardware case - just plug in the old disk and nothing
changes (well - if the Ethernet device has the same name, but a bit of
$(ifconfig -l) magic can help there, too).

Regards,
	-is