[CentOS-mirror] Some IPv6 mirrors not reachable by IPv6

Fri May 4 22:17:24 UTC 2012
Matt Domsch <Matt_Domsch at dell.com>

On Tue, May 01, 2012 at 05:14:28PM -0500, Karanbir Singh wrote:
> On 05/01/2012 10:35 PM, Anssi Johansson wrote:
> > Hi fellow mirror admins.
> > 
> > I made a list of mirrors that have a published AAAA record, and checked 
> > if those mirrors are actually reachable by IPv6. Unfortunately it looks 
> > like there is a significant amount of mirrors that do have an AAAA 
> > record, but the actual services (http, ftp, rsync) are not available by 
> > IPv6.
> > 
> 
> The aim here is to try and create, static if needed, list of mirrors to
> be served for ipv6 requests. If anyone on there wants to opt out, let us
> know now.

I think the aim would be to get the mirror admins to either a) provide
IPv6 service if they publish an AAAA record; or b) delete the AAAA
record if they don't provide IPv6 service.  Announce that policy, give
folks a week, then start dropping mirrors from the master list who
can't abide.  CentOS in particular has plenty of mirrors worldwide,
far more than many projects, with plenty of competent sysadmins.
Don't create more work for yourself to manage a (transient) list of
mirrors that have functional IPv6.

The MirrorManager crawler would, through using urlgrabber, try to
establish an IPv6 connection to a mirror with an AAAA record first.  I
don't know if it would fall back to try A records if IPv6 fails, but I
presume not.  Such failing AAAA records would then cause the crawler
to mark the mirror as not up-to-date, and automatically drop them from
the mirrorlist until such a time their AAAA record actually works.  I
say "probably" here only because Fedora's infrastructure where this
runs for them doesn't have IPv6 connectivity yet, so I haven't tested
it in production use.

Thanks,
Matt

-- 
Matt Domsch
Technology Strategist
Dell | Office of the CTO