Sent from my iPad On Jul 11, 2011, at 2:57, William Herrin <bill@herrin.us> wrote:
On Sun, Jul 10, 2011 at 4:22 PM, Owen DeLong <owen@delong.com> wrote:
On Jul 10, 2011, at 12:23 PM, William Herrin wrote:
Consider, for example, RFC 3484. That's the one that determines how an IPv6 capable host selects which of a group of candidate IPv4 and IPv6 addresses for a particular host name gets priority. How is a server's address priority NOT an issue that should be managed at an operations level by individual server administrators? Yet the working group which produced it came up with a static prioritization that is the root cause of a significant portion of the IPv6 deployment headaches we face.
3484 specifies a static default. By definition, defaults in absence of operator configuration kind of have to be static. Having a reasonable and expected set of defaults documented in an RFC provides a known quantity for what operators can/should expect from hosts they have not configured. I see nothing wrong with RFC 3484 other than I would agree that the choices made were suboptimal. Mostly that was based on optimism and a lack of experience available at the time of writing.
Hi Owen,
A more optimal answer would have been to make AAAA records more like MX or SRV records -- with explicit priorities the clients are encouraged to follow. I wasn't there but I'd be willing to bet there was a lonely voice in the room saying, hey, this should be controlled by the sysadmin. A lonely voice that got shouted down.
Uh, right, because the average system administrator wants the remote host telling his systems which address to prefer? Besides, that would have been DESTINATION address selection, not source address selection which isn't what we're talking about. I wasn't there either, but, it _IS_ controlled by the sysadmin. There are defaults in case the sysadmin is asleep at the switch (RFC 3484) and there are handles and knobs for the sysadmin to tune if he wants (the other RFC that I referred you to).
Today's RFC candidates are required to call out IANA considerations and security considerations in special sections. They do so because each of these areas has landmines that the majority of working groups are ill equipped to consider on their own.
There should be an operations callout as well -- a section where proposed operations defaults (as well as statics for which a solid case can be made for an operations tunable) are extracted from the thick of it and offered for operator scrutiny prior to publication of the RFC.
I think this would be a good idea, actually. It would probably be more effective to propose it to IETF than to NANOG, however.
If the complaint is that the IETF doesn't adequately listen to the operations folk, then I think it makes sense to consult the operations folks early and often on potential fixes. If folks here think it would help, -that- is when I'll it to the IETF.
I think it would help. Hopefully others will express similar sentiment. Owen