Thanks for tracking this down. Please find my replies inline:
На 07.03.11 11:33, Bauersachs Ingo написа:
Since r8310 the ParallelResolver DNS resolver expects an NXDOMAIN
response as soon as there is no answer, authority or additional
Yes it takes this as its cue that, since its primary resolver doesn't
seem to have any data for the domain, then maybe it would be worth
checking the backup resolver.
This causes troubles with AAAA-queries when none of these
three sections are present and NOERROR is returned. According to
RFC2308 this is a valid response (NO DATA RESPONSE: TYPE 3.). And as
far as I can tell even Google's public DNS returns NODATA for
Indeed, that would make sense for them. They only return AAAA records
for networks that they have an "arrangement" with, so returning NXDOMAIN
doesn't seem kosher in these circumstances.
Well, I'm no DNS specialist, but at least the current behavior causes
Jitsi to fall back to the backup resolvers (which are blocked at my
current network location) and trying lookups for almost three minutes
(!) until finally connecting to the SIP proxy/registrar.
I modified the check in isResponseSatisfactory to accept empty
responses for AAAA as valid, now logging in works again in a timely
Well, again, the reason that behaviour was implemented is because we
encounter such responses in many cases where records do exist and are
simply not returned by the local DNS (most often with residential
gateways). This happens regularly for NAPTR and SRV queries but it could
very well happen for AAAA as well.
I understand that what we do is causing problems in your network, but
wouldn't it make more sense to simply set an alternate backup-resolver
in your case? You can very easily do so through provisioning.
Let me know if you'd need any help with this.
The attached patch also corrects the lookup of the relevant DNS
properties. Guess what the currently present
Emil Ivov, Ph.D. 67000 Strasbourg,
Project Lead France
firstname.lastname@example.org PHONE: +18.104.22.168.43.30
http://sip-communicator.org FAX: +22.214.171.124.47.31