[dns-operations] Going to full IPv4+IPv6 in .CZ

Robin Stevens robin.stevens at oucs.ox.ac.uk
Wed Mar 10 19:44:59 UTC 2010

On Wed, Mar 10, 2010 at 11:37:16AM +0100, Shane Kerr wrote:
> On Wed, 2010-03-10 at 11:03 +0100, Ondřej Surý wrote:
> > we are going to switch our last nameserver from IPv4-only to
> > IPv4+IPv6 anycast.  Does anybody sees that as a problem?  Or should
> > we really leave one NS record just IPv4 only, because there are
> > broken clients out there, I am not aware of?
> Afilias has been running all of it's servers in dual IPv4/IPv6 mode
> for at least a year now. That means .ORG, .INFO, and a handful of
> other TLDs work without IPv4-only servers.

We recently encountered an odd issue where one morning we had a bunch
of complaints of problems in resolving .org domain names.  Our
nameservers used kernels with IPv6 support but no default v6 route and
only a scope link fe80:: address.  Yet our investigations showed these
systems were nevertheless attempting to make v6 connections and had some
very odd v6 routing table entries.  Disabling v6 support appeared to
cure the problems, but it's possible the cause was unrelated - other
pressures and the fact these servers are shortly to be replaced meant
that unfortunately we didn't investigate further.  

If as you say the .org servers have all been IPv4/IPv6 for so long, I
don't see why such a problem would have suddenly struck us so recently.

Robin Stevens <robin.stevens at oucs.ox.ac.uk>            Work +44 1865 273212
Networks & Telecommunications Group                     Fax +44 1865 273275
Oxford University Computing Services               http://www.cynic.org.uk/

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