9.5.1b1 noisy logging of EDNS errors

[Fr34k]

----- Original Message ----
From: "sthaug at nethelp.no" <sthaug at nethelp.no>
To: bind-users at isc.org
Sent: Friday, July 18, 2008 9:21:44 AM
Subject: 9.5.1b1 noisy logging of EDNS errors

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 - 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 a few minutes
if it really has been disabled...)

Steinar Haug, Nethelp consulting, sthaug at nethelp.no

With 9.5.x comes verbose logging of EDNS transactions. What does this mean? According to isc.org:
 
EDNS (Extension Mechanisms for DNS) have been available for around eight years and many servers (and all root servers) support it. Some firewalls don't support EDNS by default, some authoritative servers fail to respond to EDNS queries (instead of returning an required error), and timeouts also may be caused by network problems, dead servers, broken middle boxes, and broken authoritative servers. BIND 9.5 makes fallback to plain DNS from EDNS due to timeouts more visible. 
 
If you want to silence the logging noise, edit named.conf as follows (under “logging” section):
 
                category edns-disabled { null; };
 
Read more about EDNS in the documentation for Bind9.5.x on isc.org