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DNS Problem (I think)

travelman
Newbie
Posts: 9
Registered: 14-06-2011

DNS Problem (I think)

I have a website which I maintain which has recently refused to load on my 2 home computers which are connected to Pusnet.  However, the website loads fine on the computers of my friends and on my computer at work.
The website is www.warminstervbrd.zxq.net and is hosted by Zymic.
To make matters worse, despite refreshing and rebooting, neither of my home computers will open any website with a zxq.net extension.  The guys at Zymic have confirmed that my website is running fine and suggest that the problem could be a DNS updating problem at Plusnet.
Can anyone suggest how I can get this resolved as obviously it is making it rather difficult for me to keep my website up to date.
Any help would be appreciated.
Travelman
58 REPLIES
Community Veteran
Posts: 5,613
Thanks: 626
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Registered: 21-03-2011

Re: DNS Problem (I think)

I can see your site ok - my DNS lookup is via Demon (primary) Plusnet (secondary)
Now Zen, but a +Net residue.
VileReynard
Seasoned Pro
Posts: 10,913
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Registered: 01-09-2007

Re: DNS Problem (I think)

me too - all DNS lookups via Plusnet.

Community Veteran
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Registered: 11-08-2007

Re: DNS Problem (I think)

I too can see your site OK using my Plusnet connection, however because I use my own local caching DNS server it is very unlikely that the DNS lookup to your site was done using a Plusnet DNS.
You could try manually setting the DNS in one of your computers network properties, to say 208.67.222.222 (OpenDNS) and 8.8.8.8 (GoogleDNS).
If you can then see your site on that computer but not on the one still using the Plusnet DNS, then you will know where the problem is  Wink
Community Veteran
Posts: 4,862
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Registered: 14-07-2009

Re: DNS Problem (I think)

But I can't see the site using Plusnet DNS and Google Chrome browser.  www.zxq.net redirects to zymic.com
Community Veteran
Posts: 5,155
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Registered: 10-06-2010

Re: DNS Problem (I think)

It doesn't appear to be a DNS problem. Strangely I can ping www.warminstervbrd.zxq.net but cannot open the web page.
$ ping www.warminstervbrd.zxq.net
PING www.warminstervbrd.zxq.net (67.220.217.230) 56(84) bytes of data.
64 bytes from 67-220-217-230.hosted.static.webnx.com (67.220.217.230): icmp_req=1 ttl=54 time=160 ms
64 bytes from 67-220-217-230.hosted.static.webnx.com (67.220.217.230): icmp_req=2 ttl=54 time=161 ms
64 bytes from 67-220-217-230.hosted.static.webnx.com (67.220.217.230): icmp_req=3 ttl=54 time=160 ms
$ telnet www.warminstervbrd.zxq.net 80
Trying 67.220.217.230...
telnet: connect to address 67.220.217.230: No route to host

Wireshark tells me I got an ICMP response from 212.159.2.101 (some part of plusnet) saying Time-to-live exceeded (Time to live exceeded in transit). I'm on ptn-ag02.
Community Veteran
Posts: 4,862
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Registered: 14-07-2009

Re: DNS Problem (I think)

I'm getting a similar result to ejs.  I have changed the DNS server to Google's 8.8.8.8 and can resolve the IP address to 60.220.217.230 but I still cannot load the page.
Community Veteran
Posts: 5,155
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Registered: 10-06-2010

Re: DNS Problem (I think)

This may clarify the problem, using TCP for traceroute, on port 80:
# traceroute -T -p 80 www.warminstervbrd.zxq.net
traceroute to www.warminstervbrd.zxq.net (67.220.217.230), 30 hops max, 60 byte packets
1  192.168.0.1 (192.168.0.1)  1.801 ms  2.865 ms  4.124 ms
2  lo0-central1.ptn-ag02.plus.net (195.166.128.205)  22.795 ms  24.893 ms  26.670 ms
3  gi2-7-211.ptn-gw01.plus.net (84.92.5.137)  29.559 ms  30.660 ms  32.493 ms
4  tun0.ptn-gw01.plus.net (212.159.2.101)  34.799 ms  36.734 ms  37.685 ms
5  vl69.thn-gw2.plus.net (212.159.3.253)  39.611 ms  41.556 ms  43.045 ms
6  po4.ptn-gw01.plus.net (212.159.1.138)  46.036 ms  45.099 ms  46.398 ms
7  tun0.ptn-gw01.plus.net (212.159.2.101)  47.095 ms  29.515 ms  27.280 ms
8  vl69.thn-gw2.plus.net (212.159.3.253)  29.088 ms  28.790 ms  29.841 ms
9  po4.ptn-gw01.plus.net (212.159.1.138)  29.985 ms  29.382 ms  29.409 ms
10  tun0.ptn-gw01.plus.net (212.159.2.101)  30.954 ms *  22.258 ms
11  vl69.thn-gw2.plus.net (212.159.3.253)  24.078 ms  21.539 ms  22.420 ms
12  po4.ptn-gw01.plus.net (212.159.1.138)  24.892 ms  26.352 ms  28.065 ms
13  tun0.ptn-gw01.plus.net (212.159.2.101)  30.631 ms  32.229 ms  33.886 ms
14  vl69.thn-gw2.plus.net (212.159.3.253)  35.687 ms  37.229 ms  38.902 ms
15  po4.ptn-gw01.plus.net (212.159.1.138)  40.603 ms  42.317 ms  44.768 ms
16  tun0.ptn-gw01.plus.net (212.159.2.101)  46.541 ms  27.928 ms  28.832 ms
17  vl69.thn-gw2.plus.net (212.159.3.253)  27.999 ms  28.189 ms  28.212 ms
18  po4.ptn-gw01.plus.net (212.159.1.138)  27.797 ms  28.333 ms  28.391 ms
19  tun0.ptn-gw01.plus.net (212.159.2.101)  28.604 ms  28.829 ms  28.308 ms
20  vl69.thn-gw2.plus.net (212.159.3.253)  28.428 ms  28.527 ms  28.547 ms
21  po4.ptn-gw01.plus.net (212.159.1.138)  27.702 ms  27.872 ms  28.518 ms
22  tun0.ptn-gw01.plus.net (212.159.2.101)  29.027 ms  28.910 ms  28.361 ms
23  vl69.thn-gw2.plus.net (212.159.3.253)  28.565 ms  28.117 ms  28.518 ms
24  po4.ptn-gw01.plus.net (212.159.1.138)  27.350 ms  27.507 ms  28.210 ms
25  tun0.ptn-gw01.plus.net (212.159.2.101)  28.999 ms  29.118 ms  28.428 ms
26  vl69.thn-gw2.plus.net (212.159.3.253)  28.659 ms  28.459 ms  27.959 ms
27  po4.ptn-gw01.plus.net (212.159.1.138)  27.239 ms  27.366 ms  28.573 ms
28  tun0.ptn-gw01.plus.net (212.159.2.101)  28.414 ms  28.612 ms  27.951 ms
29  vl69.thn-gw2.plus.net (212.159.3.253)  28.957 ms  28.369 ms  29.457 ms
30  po4.ptn-gw01.plus.net (212.159.1.138)  28.319 ms  27.637 ms  27.780 ms

There's a loop. Don't ask me why it's only for port 80.
Community Veteran
Posts: 5,472
Thanks: 292
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Registered: 11-08-2007

Re: DNS Problem (I think)

Quote
$ mtr -r -c 100 www.warminstervbrd.zxq.net
HOST: my_pc                       Loss%   Snt   Last   Avg  Best  Wrst StDev
 1. my_gateway                   95.0%   100    1.7   2.7   1.4   7.0   2.4
 2. lo0-homesurf.pcl-ag07.plus.n 14.0%   100   13.7  17.0  12.8  43.3   5.3
 3. gi7-10-855.pcl-gw01.plus.net 96.0%   100   45.5  51.1  13.2 103.1  37.6
 4. po4.pcl-gw02.plus.net        10.0%   100   14.0  18.9  12.2 224.7  23.5
 5. tun0.pcl-gw01.plus.net       93.0%   100  147.7  66.9  14.2 165.4  67.8
 6. 195.50.122.129                4.0%   100   12.8  16.8  12.2 115.3  11.7
 7. ae-34-52.ebr2.London1.Level3 94.0%   100   36.7  20.4  13.3  36.7   9.1
 8. ae-41-41.ebr1.NewYork1.Level  2.0%   100   81.6  86.3  80.9 164.6  12.4
 9. ae-81-81.csw3.NewYork1.Level  3.0%   100   86.7  89.4  81.3 179.3  11.4
10. ae-82-82.ebr2.NewYork1.Level 81.0%   100   82.6  94.3  82.3 161.9  22.3
11. ae-3-3.ebr2.Dallas1.Level3.n 14.0%   100  116.5 123.4 114.9 217.5  14.0
12. ae-92-92.csw4.Dallas1.Level3  7.0%   100  116.6 121.1 114.8 266.3  16.6
13. ae-93-93.ebr3.Dallas1.Level3 90.0%   100  143.2 172.1 117.9 294.7  66.8
14. ae-3-3.ebr2.LosAngeles1.Leve  5.0%   100  156.5 157.7 153.3 245.8  12.2
15. ae-92-92.csw4.LosAngeles1.Le 13.0%   100  160.7 156.0 151.5 225.7   9.0
16. ae-4-90.edge3.LosAngeles1.Le 83.0%   100  200.9 176.2 152.4 270.6  37.0
17. cr1.lax1.us.packetexchange.n 15.0%   100  153.4 160.2 149.6 277.9  18.1
18. 67.199.135.234               85.0%   100  328.5 197.2 145.3 378.3  77.3
19. 67-220-192-106.hosted.static 93.0%   100  155.4 155.4 146.8 164.0   5.8
20. 67-220-217-230.hosted.static 92.0%   100  145.9 175.0 145.7 274.8  50.0

Still working fine using Firefox on Ubuntu with non-Plusnet DNS - despite the apparent packet losses !  Huh
travelman
Newbie
Posts: 9
Registered: 14-06-2011

Re: DNS Problem (I think)

Thank you for all you investigation guys, though I have to admit that most of it is a bit beyond me.
I think what you are saying is that is is not necessarily an issue with Plusnet as some plusnet users can open it and some can not.
EJS - your last post suggests that you may have found where the problem lies - suggestions as to what I should do next or who I should contact to get it sorted.
Travelman
Community Veteran
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Registered: 14-07-2009

Re: DNS Problem (I think)

If it was a DNS problem you could load the site by entering the IP address (60.220.217.230) into the address bar of your browser but that does not work.  Some Plusnet users seem to be able to open the site but others cannot.  ejs lost me with his loop on port 80 - can you avoid port 80 for http? 
Community Veteran
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Registered: 11-08-2007

Re: DNS Problem (I think)

I just tried the same command as 'ejs' but got different results -
Quote
$ traceroute -T -p 80 www.warminstervbrd.zxq.net
traceroute to www.warminstervbrd.zxq.net (67.220.217.230), 30 hops max, 44 byte packets
1  my_gateway                            (192.168.xxx.xxx)  2.481ms   2.507ms   4.261ms
2  lo0-homesurf.pcl-ag07.plus.net        (195.166.130.54)  18.047ms  18.635ms  *
3  * * *
4  67-220-217-230.hosted.static.webnx.com (67.220.217.230)  39.230ms  22.451ms  22.996ms
travelman
Newbie
Posts: 9
Registered: 14-06-2011

Re: DNS Problem (I think)

Just to muddy the waters further, I have just managed to load the website on my main computer by connecting it to a neighbour's non-plusnet wifi signal.  However, when I swap back to Plusnet, nothing !
To me that suggests that the problem is somehow connected to Plusnet, unless you guys can suggest some other reason.
Community Veteran
Posts: 5,472
Thanks: 292
Fixes: 4
Registered: 11-08-2007

Re: DNS Problem (I think)

@travelman,  Have you tried yet changing your PC's DNS settings as suggested in 'Reply #3' above ?
travelman
Newbie
Posts: 9
Registered: 14-06-2011

Re: DNS Problem (I think)

Sorry Purleigh, yes I have, but it made no difference I'm afraid.