IPv6 Netowrk Device Numbering BP

Thu Nov 1 05:31:57 UTC 2012

We're working out our dual stacked IPv4-IPv6 network. One
issue that recently has arisen is how to number the management
interfaces on the network devices themselves.

I have always been kind of partial to the idea of taking advantage
IPv6 features and letting hosts set their own addresses with EUI-64
interface numbers. For the management interface on a network device,
it's more like a "normal" host. I'd just as well tell the device its
prefix, and let it build the address itself. For IPv6, my opinion is
that I'm not even going to try to remember 128-bit addresses. It's
not something reasonable to expect humans to do. I'm going to depend
on some name-to-number service (DNS or a hosts file), and as far as
a computer goes, 2001:db8::80:abff:fe45:6789 is just as easy to
remember as, 2001:db8::12:34.

The other approach is to assign addresses. To me, that's more of
a hold over from IPv4 thinking, but there are legitimate reasons
I can think of. It's nice to have the IPv6 address tied to the
configuration rather than the hardware. If you need to drop in
a replacement device, you copy the configuration and no addresses
change. But OTOH, others might consider it a feature that the IP
follows the device rather than the role. And the real reason I think
people want to do it is that they want to be able to memorize IP
addresses of "important" hosts like these.

Another option would be to do both. Assign a fixed address and also
let it chose EUI-64. However, I see that leading to confusion. Not
sure what good it would do.

Is there anything like a standard, best practice for this (yet)?
What are other people doing and their reasons? Anyone have operational
experience with what works and what does not (and the "what does
not" is probably really of more interest)?
-- 
Crist J. Clark