Images loading very slow for German telekom users

[ictag]

Hi,

This is repeat of  a situation we had many years ago. Unfortunately, the old discussion thread seems to have been deleted.

Symptom: images don't load, or take extremely long to load (over 15 minutes on dsl connections). Affected are foreign servers (e.g. facebook or bbc) for German Telekom customers. E.g. the BBC news website displays the text but not the images of the news items on the bbc News app (mobile devices) or website.

Cause: Last time we discovered that this was due to a lack of dns sync of the provider's servers. Wish I could access the old thread which had the details.

Frequency: Sporadic. Depends on the time of day, but last time it went on for several months before resolving itself somehow.

Solution: Switch off opendns dns and use Telekom or Google's dns routers instead until the problem is resolved by the provider.

Tom

[rotblitz]

I doubt that this is an OpenDNS problem.  And I do not have any troubles with images or other content at a Telekom VDSL2 connection, especially not with Facebook or BBC.  Therefore I also doubt that switching to a different DNS service is the solution for this sporadic problem.

If you think it is different and related to OpenDNS, come up with clear measuring results, not with rumours.

"This is repeat of a situation we had many years ago"

Don't worry.  It's highly unlikely that this problem was related in any way.  So many things have changed since then.  Or better: nearly nothing is still the same nowadays.

[ictag]

Hi Rotblitz,

It's not a rumour. This was discussed and analyzed in a very lengthy and detailed thread in the opendns forum  in 2011/2012.

But you're right, maybe there's a different root-cause even though the symptoms and cure are identical. But since it was really tricky doing the analysis last time round it would really help find an alternative cure if opendns could access an archive of the thread. The ticket I created from the thread was: #QKD-35233-581,

[rotblitz]

"Many years ago" there was a different forum and forum platform which has been taken offline in the meantime.  I do not see a way to make it visible again unless it was captured by web.archive.org.

The "tricky" measuring for your symptoms would be as follows (and most likely the same as many years ago):

• You identify the exact URLs of the images which do not load or take a long time to load.
• You raise DNS lookups for the related domain against OpenDNS and against the other DNS services to compare the results.  If the results are identical, then you're done.  The problem is not related to OpenDNS.  If not...
• You perform traceroutes to the IP addresses returned from the previous step to see if there are significant differences.  If there are none, then you're done, because it is not OpenDNS related.
• To continue investigating outside the scope of DNS, you would try to load the dedicated image URL in different browsers or even better with a diagnostic tool like wget or cURL to see what comes out.  Possible causes can be the dedicated server where the images are hosted on, or a specific condition with your Telekom internet connection at the location where you are.

Edit: And yes, the old forum is still visible via http://web.archive.org/web/*/forums.opendns.com