[SR-Users] NAPTR/SRV lookups fail when use_dns_failover is enabled.

Mon Jan 23 22:49:37 CET 2017

It was the port in the LCR table! You're the man! Thanks so much for your
help.

On Mon, Jan 23, 2017 at 12:45 AM, Carsten Bock <carsten at ng-voice.com> wrote:

> Hi,
>
> can you try the sip-dig command on that particular domain?
> If you set that domain in script or from a module (e.g. Dispatcher),
> don't set a port. According to RFC 3263, the DNS-records are treated
> differently, if no port is set (e.g. "redacted.hostname.here.com:5060"
> will produce a different result than "redacted.hostname.here.com").
> I've checked the compliance of Kamailio with RFC 3263 in the past, as
> DNS-Failover is mandatory for IMS.
>
> I would find it rather strange, if it should work correct in all of
> our deployments and not in yours.
>
> Thanks,
> Carsten
>
> 2017-01-20 17:47 GMT+01:00 Jeremy Gadd <jeremygadd at gmail.com>:
> > Thanks for the response!
> >
> > DNS lookups work in Kamailio as long as use_dns_failover is set to "off."
> > It's only when the failover is enabled that they break. I think this
> means
> > it's not a DNS issue, but something in Kamailio.
> >
> > I should mention we're pointing to Verizon's services with many many
> > thousands of customers, so it's unlikely to be misconfigured DNS (unless
> > it's something local that only breaks when use_dns_failover is enabled?)
> >
> > On Fri, Jan 20, 2017 at 12:37 AM, Carsten Bock <carsten at ng-voice.com>
> wrote:
> >>
> >> Hi,
> >>
> >> we have the following settings and those work fine for us (Kamailio 4
> >> and later):
> >>
> >> # Do SRV-Loadbalancing:
> >> dns_srv_lb=yes
> >> # Always prefer IPv6:
> >> dns_try_ipv6=yes
> >> # DNS-Based failover
> >> use_dns_failover=yes
> >> # Query NAPTR-Records as well (we use NAPTR, so the client can detect
> >> the outbound Proxy (P-CSCF), but internally we only use only
> >> SRV-records)
> >> dns_try_naptr=no
> >>
> >> Sounds to me, like a DNS problem, not a Kamailio problem.
> >>
> >> In our DNS Zone, we have the following, for example:
> >>
> >> wt                      1D IN A         84.46.93.82
> >> wt                      1D IN A         84.46.93.84
> >> wt-1            1D IN A         84.46.93.82
> >> wt-2            1D IN A         84.46.93.84
> >> wt              1D IN NAPTR 10 10 "s" "SIP+D2U"         ""
> >> _sip._udp.wt
> >>
> >> _sip._udp.wt    1D SRV 10 1 5060 wt-1
> >> _sip._udp.wt    1D SRV 20 1 5060 wt-2
> >>
> >> On Debian/Ubuntu, you can verify this with Sofia-SIP (apt-get install
> >> sofia-sip-bin):
> >>
> >> carsten at carsten-HP-EliteBook-840-G3:~$ sip-dig wt.ng-voice.com
> >> 1 1.000 udp 5060 84.46.93.82
> >> 2 1.000 udp 5060 84.46.93.84
> >>
> >> Thanks,
> >> Carsten
> >>
> >>
> >> 2017-01-19 22:58 GMT+01:00 Jeremy Gadd <jeremygadd at gmail.com>:
> >> > Hello, everyone!
> >> >
> >> > I'm trying to enable dns_srv_lb but I'm stuck just before I can get
> >> > there.
> >> > If I don't enable use_dns_failover, lookups work and calls route but
> >> > always
> >> > to the first host. We need to load balance, so that doesn't work very
> >> > well.
> >> >
> >> > If I enable use_dns_failover, the lookups stop working completely and
> we
> >> > get
> >> > a dns lookup failure like so:
> >> >  ERROR: tm [ut.h:296]: uri2dst2(): ERROR: uri2dst: failed to resolve
> >> > "redacted.hostname.here.com" :unresolvable A or AAAA request (-7)
> >> >
> >> > This works:
> >> > use_dns_cache=on
> >> > dns_use_search_list=no
> >> > dns_try_naptr=on
> >> > # use_dns_failover=on
> >> >
> >> > This breaks it:
> >> > use_dns_cache=on
> >> > dns_use_search_list=no
> >> > dns_try_naptr=on
> >> > use_dns_failover=on
> >> >
> >> > I have checked to see that use_dns_failover is compiled in:
> >> > version: kamailio 4.4.2 (x86_64/linux)
> >> > flags: STATS: Off, USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS,
> USE_RAW_SOCKS,
> >> > DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MEM, SHM_MMAP, PKG_MALLOC,
> >> > Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX,
> >> > FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR,
> >> > USE_DST_BLACKLIST, HAVE_RESOLV_RES
> >> > ADAPTIVE_WAIT_LOOPS=1024, MAX_RECV_BUFFER_SIZE 262144, MAX_LISTEN 16,
> >> > MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB
> >> > poll method support: poll, epoll_lt, epoll_et, sigio_rt, select.
> >> > id: unknown
> >> > compiled with gcc 4.9.2
> >> >
> >> > _______________________________________________
> >> > SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing
> list
> >> > sr-users at lists.sip-router.org
> >> > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
> >> >
> >>
> >>
> >>
> >> --
> >> Carsten Bock
> >> CEO (Geschäftsführer)
> >>
> >> ng-voice GmbH
> >> Millerntorplatz 1
> >> 20359 Hamburg / Germany
> >>
> >> http://www.ng-voice.com
> >> mailto:carsten at ng-voice.com
> >>
> >> Office +49 40 5247593-40
> >> Fax +49 40 5247593-99
> >>
> >> Sitz der Gesellschaft: Hamburg
> >> Registergericht: Amtsgericht Hamburg, HRB 120189
> >> Geschäftsführer: Carsten Bock
> >> Ust-ID: DE279344284
> >>
> >> Hier finden Sie unsere handelsrechtlichen Pflichtangaben:
> >> http://www.ng-voice.com/imprint/
> >>
> >> _______________________________________________
> >> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
> >> sr-users at lists.sip-router.org
> >> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
> >
> >
> >
> > _______________________________________________
> > SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
> > sr-users at lists.sip-router.org
> > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
> >
>
>
>
> --
> Carsten Bock
> CEO (Geschäftsführer)
>
> ng-voice GmbH
> Millerntorplatz 1
> 20359 Hamburg / Germany
>
> http://www.ng-voice.com
> mailto:carsten at ng-voice.com
>
> Office +49 40 5247593-40
> Fax +49 40 5247593-99
>
> Sitz der Gesellschaft: Hamburg
> Registergericht: Amtsgericht Hamburg, HRB 120189
> Geschäftsführer: Carsten Bock
> Ust-ID: DE279344284
>
> Hier finden Sie unsere handelsrechtlichen Pflichtangaben:
> http://www.ng-voice.com/imprint/
>
> _______________________________________________
> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
> sr-users at lists.sip-router.org
> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>
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