Clients get DNS timeouts because ipv6 means more queries for each lookup

Eivind Olsen eivind at
Mon Jul 11 19:26:29 UTC 2011

Jonathan Kamens wrote:

> I said above that the problem is exacerbated by the fact that many DNS
> servers don't yet support IPV6 queries. This is because the AAAA queries
> don't get NXDOMAIN responses, which would be cached, but rather FORMERR
> responses, which are not cached. As a result, the scenario describes
> above happens much more frequently because the DNS server has to redo
> the AAAA queries often.

I think the main issue here is - why is your nameserver thinking it has
IPv6 connectivity?
If you don't have a working IPv6 connectivity, do one / both of these:

1) Disable or at least configure IPv6 properly on your server
2) Tell BIND to not use IPv6 transport, typically by starting "named" with
the command line option "-4". How to do that depends on your operating
system / distribution / packaging system etc.

Eivind Olsen

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