9.5.1b1 noisy logging of EDNS errors

[Kevin Darcy]

sthaug at nethelp.no wrote:
> Running 9.5.1b1 on FreeBSD 7-STABLE.
>
> I assume the noisiness of this log message is deliberate:
>
> Jul 18 14:38:22 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> Jul 18 14:38:22 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> ...
> Jul 18 14:45:20 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> Jul 18 14:45:20 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> ...
> Jul 18 14:53:01 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> Jul 18 14:53:01 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> ...
> Jul 18 15:00:33 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> Jul 18 15:00:33 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> ...
> Jul 18 15:08:06 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> Jul 18 15:08:06 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> ...
> Jul 18 15:16:00 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
> Jul 18 15:16:00 slem2 named[10514]: too many timeouts resolving '16.69.17.209.in-addr.arpa/PTR' (in '69.17.209.in-addr.arpa'?): disabling EDNS
>
> But this begs the question - 
I think you mean "begets the question". See 
http://en.wikipedia.org/wiki/Begs_the_question
> is there any kind of rate limiting of these
> messages? And when it logs 'disabling EDNS', for how *long* does it stay
> disabled? (Seems strange to log the same message again after only a few
> minutes if it really has been disabled...)
>   
My understanding is that the EDNS disablement only applies to that 
particular query, and named doesn't remember EDNS deficiencies from 
query to query. This is based on a cursory examination of the code, I 
could be wrong.

You can, of course, proactively disable EDNS for specific servers in 
named.conf.

There doesn't seem to be any rate limiting of the messages either.

- Kevin