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Vanilla 1.1.4 is a product of Lussumo. More Information: Documentation, Community Support.

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    • CommentAuthordoinx
    • CommentTimeJun 13th 2012
     permalink
    My network has had a fixed public address for a long time, and I've enjoyed the benefits of OpenDNS. However, lately - during the last week or two - there have been problems with loading facebook; it just times out. If I change the router setup to use my ISP's DNS servers the page loads in an instant. So facebook does not appear to be blocked (no indication of that) - it just doesn't load when I use OpenDNS, and this started happening just some days ago (there have been days in between when it heen ok, but the last 2-3 days, no luck). I've even removed all filtering from my OpenDNS settings (and flushed caches, etc.), just in case.

    Anything else I could try?
    • CommentAuthorrotblitz
    • CommentTimeJun 13th 2012
     permalink
    You would need to open a support ticket for OpenDNS staff looking into it, or you must post the complete output of the following commands, enabling us users to look into it. It's your choice.
    (Trailing dots are part of the commands!)

    First ensure that you have your ISP's DNS enabled.

    nslookup www.facebook.com.
    nslookup www.facebook.com. 208.67.222.222
    nslookup static.ak.fbcdn.net.
    nslookup static.ak.fbcdn.net. 208.67.222.222
    nslookup -type=txt debug.opendns.com. 208.67.222.222

    After I have seen it, I may ask for more...
    • CommentAuthordoinx
    • CommentTimeJun 14th 2012
     permalink
    Here are the results, the DNSs definitely point to different addresses:

    >nslookup www.facebook.com.
    Server: bbsrv5.loqal.no
    Address: 82.194.192.38

    Non-authoritative answer:
    Name: www.facebook.com
    Addresses: 2a03:2880:2110:3f01:face:b00c::
    69.63.190.70


    >nslookup www.facebook.com. 208.67.222.222
    Server: resolver1.opendns.com
    Address: 208.67.222.222

    Non-authoritative answer:
    Name: www.facebook.com
    Addresses: 2a03:2880:2110:3f01:face:b00c::
    69.171.247.21


    >nslookup static.ak.fbcdn.net.
    Server: bbsrv5.loqal.no
    Address: 82.194.192.38

    Non-authoritative answer:
    Name: a749.dsw4.akamai.net
    Addresses: 2001:6c8:160::c3d7:2519
    2001:6c8:160::c3d7:252f
    195.215.221.91
    195.215.221.73
    Aliases: static.ak.fbcdn.net
    static.ak.facebook.com.edgesuite.net


    >nslookup static.ak.fbcdn.net. 208.67.222.222
    Server: resolver1.opendns.com
    Address: 208.67.222.222

    Non-authoritative answer:
    Name: a749.dsw4.akamai.net
    Addresses: 2001:680:12:500::3e29:1268
    2001:680:12:500::3e29:126a
    77.67.27.26
    77.67.27.56
    Aliases: static.ak.fbcdn.net
    static.ak.facebook.com.edgesuite.net


    >nslookup -type=txt debug.opendns.com. 208.67.222.222
    Server: resolver1.opendns.com
    Address: 208.67.222.222

    Non-authoritative answer:
    debug.opendns.com text =

    "server 7.fra"
    debug.opendns.com text =

    "flags 20 0 2fe 0"
    debug.opendns.com text =

    "id 7976929"
    debug.opendns.com text =

    "source <my public ip>:57365"
    • CommentAuthorrotblitz
    • CommentTimeJun 14th 2012
     permalink
    You are suboptimally routed by your Norwegian ISP and peering network carriers.

    They route you to the OpenDNS Frankfurt/Germany location, and this provides you with IP address information for German CDN servers, whereas your ISP's DNS provides you with IP address information for Danish CDN servers.

    Not much we users like you could do against...

    I said: "After I have seen it, I may ask for more...". Here it is:
    tracert 195.215.221.91
    tracert 77.67.27.26

    Whatever, best would be to open a support ticket including a link to this thread.
    https://dashboard.opendns.com/support/

    Just for information, here the location information about the participating IP addresses:

    Hostname Country Code Country Name Region Region Name City Postal Code Latitude Longitude ISP Organization Metro Code Area Code
    69.63.190.70 US United States CA California Palo Alto 94301 37.4429 -122.1514 Facebook Facebook 807 650
    69.171.247.21 US United States CA California Palo Alto 94304 37.3762 -122.1826 Facebook Facebook 807 650
    195.215.221.91 DK Denmark 56.0000 10.0000 Tele Danmark Tele Danmark
    195.215.221.73 DK Denmark 56.0000 10.0000 Tele Danmark Tele Danmark
    77.67.27.26 DE Germany 51.0000 9.0000 Tinet SpA Akamai Technologies
    77.67.27.56 DE Germany 51.0000 9.0000 Tinet SpA Akamai Technologies
    82.194.192.38 NO Norway 16 Sor-Trondelag Orkanger 63.3167 9.8667 Loqal AS LOQAL - Rennebu Servers
    • CommentAuthordoinx
    • CommentTimeJun 14th 2012
     permalink
    Thanks, rotblitz! I've now opened a ticket. For what it is worth, here are the results from the last two tests:

    Tracing route to a195-215-221-91.deploy.akamaitechnologies.com [195.215.221.91]
    over a maximum of 30 hops:

    1 * * * Request timed out.
    2 9 ms 9 ms 7 ms 188.113.65.49
    3 16 ms 9 ms 9 ms 82.194.192.5
    4 12 ms 18 ms 19 ms 82.194.192.1
    5 27 ms 8 ms 8 ms 213.236.164.249
    6 24 ms 24 ms 25 ms ae-1.alb2nqp7.dk.ip.tdc.net [83.88.21.83]
    7 26 ms 25 ms 24 ms a195-215-221-91.deploy.akamaitechnologies.com [195.215.221.91]


    Trace complete.

    Tracing route to 77.67.27.26 over a maximum of 30 hops

    1 * * * Request timed out.
    2 397 ms 10 ms 7 ms 188.113.65.49
    3 11 ms 9 ms 19 ms 82.194.192.5
    4 16 ms 15 ms 15 ms te3-5.ccr01.osl01.atlas.cogentco.com [149.6.116.57]
    5 31 ms 31 ms 31 ms te0-1-0-5.ccr21.ham01.atlas.cogentco.com [130.117.2.177]
    6 42 ms 41 ms 41 ms te0-4-0-3.mpd21.fra03.atlas.cogentco.com [154.54.63.29]
    7 39 ms 40 ms 41 ms xe-4-3-0.fra23.ip4.tinet.net [77.67.74.41]
    8 40 ms 41 ms 40 ms 77.67.27.26

    Trace complete.
    • CommentAuthorrotblitz
    • CommentTimeJun 14th 2012
     permalink
    The first traceroute is to a Danish CDN server serving content for Facebook, and the second is to a German CDN server. The latency is not bad for Germany either. This alone may not explain your problems.

    Let's see what OpenDNS staff will find out.
    • CommentAuthordoinx
    • CommentTimeJun 19th 2012
     permalink
    The staff hasn't come up with a likely cause or solution yet. However; more or less by chance I started pinging facebook.com with various buffer sizes when connected to OpenDNS (in router). That's when I noticed that I got a reply for sizes below 1472 bytes. My router has a default MTU of 1500. So I reduced the MTU in the router setup to 1472, and now I can open the facebook web site.

    So what I don't understand is: why would the use of OpenDNS affect this? Does OpenDNS route my request through nodes that don't allow buffer sizes above 1472 bytes, while my ISP's DNS servers avoid such problems??
    Thankful People: rotblitz, zelus
    • CommentAuthorrotblitz
    • CommentTimeJun 19th 2012
     permalink
    Wow, MTU change is a suprising but not unexpected solution!

    Yes, this can indeed explain your problems. It is not really related to OpenDNS, but with what IP address information they are fed. And I know that certain CDN servers react sensibly on such communication attributes. I could have thought about this.

    You may optimize your computer settings as well at this occasion:
    http://www.speedguide.net/downloads.php

This discussion has been inactive for longer than 30 days, and is thus closed.