Bug 11113

Summary: nsupdate.info: ddns is sending updates even if IP address has not changed
Product: DDNS Updater Reporter: Timmothy Wilson <itsuperhack>
Component: ProvidersAssignee: Stefan Schantl <stefan.schantl>
Status: CLOSED NOTABUG QA Contact: Michael Tremer <michael.tremer>
Severity: - Unknown -    
Priority: - Unknown -    
Version: unspecified   
Hardware: unspecified   
OS: Unspecified   
Attachments: screenshot of the ddns log section in the WebIF
pppoe log section in the WebIF

Description Timmothy Wilson 2016-05-03 08:15:39 UTC
Created attachment 440 [details]
screenshot of the ddns log section in the WebIF

Today, nsupdate.info flagged my host as abusive.

As the logs for ddns and pppoe connection show, ddns is sending updates even if the public IP address of the IPFire system has not changed meanwhile.

Since ddns seems to work with other providers, such as changeip, dynu.com, etc., this appears to be a bug.

My system worked well with the nsupdate.info ddns service until a while ago, but there were power outages (and no such log entries appeared). This time it seems
to be a bug in the ddns updater itself.
Comment 1 Timmothy Wilson 2016-05-03 08:16:16 UTC
Created attachment 441 [details]
pppoe log section in the WebIF
Comment 2 Michael Tremer 2016-05-03 12:48:15 UTC
What is the hostname of this machine?
Comment 3 Timmothy Wilson 2016-05-05 17:56:22 UTC
(In reply to Michael Tremer from comment #2)
> What is the hostname of this machine?

trikolon-de204

Host is offline at the moment, and this seems to be a problem which is not hostname-related: https://forum.ipfire.org/viewtopic.php?f=27&t=16487
Comment 4 Michael Tremer 2016-05-06 22:31:07 UTC
Sorry for asking the question wrong. I was rather asking if the hostname of the system matches the dynamic DNS name. In that case the local internal IP address will be resolved which causes a mismatch and might trigger a DNS update.

Is there more logs?
Comment 5 Timmothy Wilson 2016-05-07 09:07:23 UTC
(In reply to Michael Tremer from comment #4)
> Sorry for asking the question wrong. I was rather asking if the hostname of
> the system matches the dynamic DNS name. In that case the local internal IP
> address will be resolved which causes a mismatch and might trigger a DNS
> update.
No, the systems hostname is "firewall".
> 
> Is there more logs?
Not really, the ddns log of the last few days before I opened this showed the same as the attached screenshot of the "ddns log" does: Many successful updates for the nsupdate.info domain.

Since I disabled the host momentarily, there are no logs anymore for nsupdate.info.
Comment 6 Michael Tremer 2016-05-07 14:13:08 UTC
Can you confirm that you get back the correct IP address if you manually resolve that hostname on the firewall?
Comment 7 Timmothy Wilson 2016-05-07 15:43:13 UTC
(In reply to Michael Tremer from comment #6)
> Can you confirm that you get back the correct IP address if you manually
> resolve that hostname on the firewall?

I think so:

[root@firewall ~]# date
Sat May  7 15:41:03 CEST 2016
[root@firewall ~]# host trikolon-de204.nsupdate.info
Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
[root@firewall ~]# ddns update trikolon-de204.nsupdate.info --force
Dynamic DNS update for trikolon-de204.nsupdate.info (nsupdate.info) successful
[root@firewall ~]# date
Sat May  7 15:41:36 CEST 2016
[root@firewall ~]# host trikolon-de204.nsupdate.info
Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
[root@firewall ~]# host trikolon-de204.nsupdate.info
Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
[root@firewall ~]# host trikolon-de204.nsupdate.info
trikolon-de204.nsupdate.info has address 188.97.[REDACTED]
[root@firewall ~]# date
Sat May  7 15:42:21 CEST 2016
[root@firewall ~]#
Comment 8 Michael Tremer 2016-05-09 00:42:28 UTC
(In reply to Timmothy Wilson from comment #7)
> (In reply to Michael Tremer from comment #6)
> > Can you confirm that you get back the correct IP address if you manually
> > resolve that hostname on the firewall?
> 
> I think so:
> 
> [root@firewall ~]# date
> Sat May  7 15:41:03 CEST 2016
> [root@firewall ~]# host trikolon-de204.nsupdate.info
> Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
> [root@firewall ~]# ddns update trikolon-de204.nsupdate.info --force
> Dynamic DNS update for trikolon-de204.nsupdate.info (nsupdate.info)
> successful
> [root@firewall ~]# date
> Sat May  7 15:41:36 CEST 2016
> [root@firewall ~]# host trikolon-de204.nsupdate.info
> Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
> [root@firewall ~]# host trikolon-de204.nsupdate.info
> Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
> [root@firewall ~]# host trikolon-de204.nsupdate.info
> trikolon-de204.nsupdate.info has address 188.97.[REDACTED]
> [root@firewall ~]# date
> Sat May  7 15:42:21 CEST 2016
> [root@firewall ~]#

So this looks quite good so far. Do you have the log files from that day after 15:42 CEST? Would be interesting to know if ddns tried to update again.
Comment 9 Timmothy Wilson 2016-05-11 18:22:21 UTC
(In reply to Michael Tremer from comment #8)
> (In reply to Timmothy Wilson from comment #7)
> > (In reply to Michael Tremer from comment #6)
> > > Can you confirm that you get back the correct IP address if you manually
> > > resolve that hostname on the firewall?
> > 
> > I think so:
> > 
> > [root@firewall ~]# date
> > Sat May  7 15:41:03 CEST 2016
> > [root@firewall ~]# host trikolon-de204.nsupdate.info
> > Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
> > [root@firewall ~]# ddns update trikolon-de204.nsupdate.info --force
> > Dynamic DNS update for trikolon-de204.nsupdate.info (nsupdate.info)
> > successful
> > [root@firewall ~]# date
> > Sat May  7 15:41:36 CEST 2016
> > [root@firewall ~]# host trikolon-de204.nsupdate.info
> > Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
> > [root@firewall ~]# host trikolon-de204.nsupdate.info
> > Host trikolon-de204.nsupdate.info not found: 3(NXDOMAIN)
> > [root@firewall ~]# host trikolon-de204.nsupdate.info
> > trikolon-de204.nsupdate.info has address 188.97.[REDACTED]
> > [root@firewall ~]# date
> > Sat May  7 15:42:21 CEST 2016
> > [root@firewall ~]#
> 
> So this looks quite good so far. Do you have the log files from that day
> after 15:42 CEST? Would be interesting to know if ddns tried to update again.

No, it didn't. Since 15:42 CEST, everything is running fine, there are no days with more than one update try for nsupdate.info.

I thereof assume we can close this, since it was a bug at nsupdate.info. Arne guessed in the forum that they didn't pass the updated IP to the DNS; thats my opinion, too.

What do you think about that?
Comment 10 Timmothy Wilson 2016-05-18 10:23:21 UTC
Everything is working fine here, no errors appeared since my last post.
Closing this issue as "NOTABUG", since it was a problem at nsupdate.info (probably).
Comment 11 Michael Tremer 2016-05-18 14:30:38 UTC
Okay, thanks. Reopen if the problem comes back.