Do Some Gateways Block Certain Sites?

[#1]

The problem was that it caused certain sites not to load instead they  timed out. I'm guessing that was a similar thing with updating Malwarebytes where the updates didn't exactly time out but took much longer to connect and load making the program enter a temporary not responding phase.
Not sure myself if this is anything to do with DNS but it's always interesting to read these technical asides.

[#2]

It sounds like MTU to me.
I find that if this page - https://signin.ebay.co.uk, doesn't load then MTU on router is too high.
My previous Linksys routers used to be happy with MTU=1500,  but my current Netgear DG834GT gives best results with MTU=1430, with no loss of download speed.

[#3]

That page works OK for me with MTU 1500.
Did you try gateway hopping?

[#4]

I don't think it's due to MTU as after gateway hopping the site loads perfectly fine. Seems like a gateway issue to me, some misconfiguration somewhere.
I've seen it happen a couple of times before and changing gateway always fixes it. Unfortunately I didn't check which gateway it was at the time but in the previous post I did get one.

[#5]

[quote=Jelv]Did you try gateway hopping?
If that question is for me, then I gateway hop every time I notice that my connection is running slowly, but have set my MTU so that my connection ALWAYS works.
I can't say that I have ever noticed a correlation between sites not loading and which gateway I'm on - but I have not been looking for that, only how to get the best speedtests with all pages I visit being accessible AND zero packet resends or fragmentation.
As you can see from my signature below, I get speedtest results that match the maximum theoretical IP profile possible (7150Kbps) on my 8Mb 20CN connection, using the MTU=1430.
I'm happy with my connection and see no advantage in trying to achieve a higher MTU.
I can load problematic pages with a higher MTU (like 1458), but packet losses start to appear when doing speedtests or large file transfers.

[#6]

Quote from: RPMozley

I don't think it's due to MTU as after gateway hopping the site loads perfectly fine.

That makes me think a MTU issue is a possibility - on the gateway itself or somewhere in the BT network.
Here's a previous issue:
http://community.plus.net/forum/index.php?topic=31484.0 and http://usergroup.plus.net/forum/index.php/topic,4411.0.html
There have been other similar issues in the past when new gateways are introduced.

[#7]

What besides some web filtering is going to explain getting a different traceroute to tcp port 80 than to any other tcp port or packet type?
Here are the previous instances of loops in the routing on ptn gateways:
http://community.plus.net/forum/index.php/topic,96555.msg814238.html#msg814238
http://community.plus.net/forum/index.php/topic,103624.0.html
The exact error message if the problem is a loop in the routing should be something like: destination unreachable - TTL exceeded.

[#8]

MTU...... unless Windows 7? IIRC it's set automatically or something like that, so fiddling not recommended.

[#9]

I reconnected this morning, here is the traceroute from ptn-ag04

traceroute -T -p 80 www.filefactory.com
traceroute to www.filefactory.com (85.17.172.100), 30 hops max, 60 byte packets
 1  192.168.0.1 (192.168.0.1)  4.351 ms  4.687 ms  5.582 ms
 2  lo0-central5.ptn-ag04.plus.net (195.166.130.83)  22.481 ms  25.222 ms  26.373 ms
 3  84.93.253.83 (84.93.253.83)  28.185 ms  31.624 ms  32.047 ms
 4  po4.ptn-gw01.plus.net (212.159.1.138)  34.191 ms  35.452 ms  37.842 ms
 5  tun0.ptn-gw01.plus.net (212.159.2.101)  39.100 ms  41.584 ms  42.735 ms
 6  vl69.ptw-gw02.plus.net (212.159.3.253)  44.520 ms  41.340 ms  43.225 ms
 7  po4.ptn-gw01.plus.net (212.159.1.138)  45.157 ms  29.244 ms  29.375 ms
 8  tun0.ptn-gw01.plus.net (212.159.2.101)  29.147 ms  28.459 ms  28.821 ms
 9  vl69.ptw-gw02.plus.net (212.159.3.253)  29.616 ms  29.895 ms  29.594 ms
10  po4.ptn-gw01.plus.net (212.159.1.138)  29.558 ms  19.213 ms  21.018 ms
11  tun0.ptn-gw01.plus.net (212.159.2.101)  23.435 ms  19.262 ms  22.138 ms
12  vl69.ptw-gw02.plus.net (212.159.3.253)  23.216 ms  25.023 ms  26.548 ms
13  po4.ptn-gw01.plus.net (212.159.1.138)  28.879 ms  31.378 ms  31.897 ms
14  tun0.ptn-gw01.plus.net (212.159.2.101)  34.995 ms  35.330 ms  37.909 ms
15  vl69.ptw-gw02.plus.net (212.159.3.253)  40.179 ms  41.365 ms  44.378 ms
16  po4.ptn-gw01.plus.net (212.159.1.138)  44.899 ms  47.262 ms  30.423 ms
17  tun0.ptn-gw01.plus.net (212.159.2.101)  30.052 ms  30.401 ms  30.458 ms
18  vl69.ptw-gw02.plus.net (212.159.3.253)  28.778 ms  29.327 ms  29.936 ms
19  po4.ptn-gw01.plus.net (212.159.1.138)  30.197 ms  29.872 ms  30.950 ms
20  tun0.ptn-gw01.plus.net (212.159.2.101)  30.615 ms  30.789 ms  30.154 ms
21  vl69.ptw-gw02.plus.net (212.159.3.253)  31.518 ms  31.184 ms  30.430 ms
22  po4.ptn-gw01.plus.net (212.159.1.138)  31.414 ms  30.403 ms  30.267 ms
23  tun0.ptn-gw01.plus.net (212.159.2.101)  30.082 ms  31.281 ms  30.224 ms
24  vl69.ptw-gw02.plus.net (212.159.3.253)  30.237 ms  29.632 ms  29.739 ms
25  po4.ptn-gw01.plus.net (212.159.1.138)  30.070 ms  29.487 ms  30.609 ms
26  tun0.ptn-gw01.plus.net (212.159.2.101)  30.477 ms  27.872 ms  28.502 ms
27  vl69.ptw-gw02.plus.net (212.159.3.253)  29.217 ms  28.200 ms  28.881 ms
28  po4.ptn-gw01.plus.net (212.159.1.138)  30.075 ms  29.675 ms  30.415 ms
29  tun0.ptn-gw01.plus.net (212.159.2.101)  30.865 ms  29.969 ms  31.731 ms
30  vl69.ptw-gw02.plus.net (212.159.3.253)  29.691 ms  29.071 ms  29.593 ms

[#10]

Ok, I'm going to mention an apparent related issue as I don't know if it got looked at, as no ticket was raised.
After the network came back up after the last crash (Thursday 19th) I did some Gateway hopping. I landed on 195.166.130.100 I'm afraid I didn't make any further notes or check the gateway name (or do any other tests) - I just couldn't browse anywhere, zilch.   IP address at the time was 31.185.224.136 (my MTU is 1500 in case MTU becomes relevant) (20CN as well).
I just hopped to another gateway and carried on with what I was doing before the crash.

[#11]

What does anyone make of these results?
Tracing route to filefactory.com [85.17.172.100]
over a maximum of 30 hops:
  1     1 ms    <1 ms    <1 ms  RTA1335.home [192.168.1.1]
  2    35 ms    36 ms    37 ms  lo0-central3.pcl-ag02.plus.net [195.166.128.237]
  3    81 ms    34 ms    34 ms  gi1-23-232.pcl-gw02.plus.net [84.92.6.50]
  4    38 ms    33 ms    34 ms  tun0.pcl-gw01.plus.net [212.159.2.105]
  5    36 ms    34 ms    34 ms  flowers2.servers.plus.net.uk [212.159.2.98]
  6    36 ms  3807 ms    35 ms  xe-11-1-0.edge3.London2.Level3.net [212.187.201.209]
  7    34 ms    35 ms    34 ms  ae-0-11.edge4.London2.Level3.net [4.69.200.126]
  8    35 ms    34 ms    34 ms  ae-3-3.ebr1.London1.Level3.net [4.69.141.189]
  9    35 ms    35 ms    35 ms  vlan101.ebr2.London1.Level3.net [4.69.143.86]
10    41 ms    44 ms    44 ms  ae-45-45.ebr2.Amsterdam1.Level3.net [4.69.143.69]
11    47 ms    49 ms    49 ms  ae-56-221.csw2.Amsterdam1.Level3.net [4.69.153.202]
12    83 ms    42 ms    44 ms  4.69.162.150
13    42 ms    47 ms    47 ms  FIBERRING-B.edge5.Amsterdam1.Level3.net [212.72.41.142]
14    41 ms    44 ms    44 ms  po100.hv1.evo.leaseweb.net [85.17.100.222]
15    52 ms    51 ms    50 ms  www.filefactory.com [85.17.172.100]
Trace complete.
Tracing route to filefactory.com [85.17.172.100]
over a maximum of 30 hops:
  1    <1 ms    <1 ms    <1 ms  RTA1335.home [192.168.1.1]
  2    95 ms   129 ms   114 ms  lo0-central3.pcl-ag02.plus.net [195.166.128.237]
  3   241 ms   232 ms   325 ms  gi1-23-232.pcl-gw02.plus.net [84.92.6.50]
  4    61 ms   329 ms   218 ms  tun0.pcl-gw01.plus.net [212.159.2.105]
  5    34 ms    35 ms    34 ms  flowers2.servers.plus.net.uk [212.159.2.98]
  6    36 ms    34 ms    35 ms  xe-11-1-0.edge3.London2.Level3.net [212.187.201.209]
  7    34 ms    34 ms    34 ms  ae-0-11.edge4.London2.Level3.net [4.69.200.126]
  8    37 ms    34 ms    34 ms  ae-3-3.ebr1.London1.Level3.net [4.69.141.189]
  9    34 ms    36 ms    37 ms  vlan101.ebr2.London1.Level3.net [4.69.143.86]
10    44 ms    44 ms    45 ms  ae-45-45.ebr2.Amsterdam1.Level3.net [4.69.143.69]
11    53 ms    49 ms    49 ms  ae-56-221.csw2.Amsterdam1.Level3.net [4.69.153.202]
12    41 ms    43 ms    44 ms  4.69.162.150
13    47 ms    47 ms    47 ms  FIBERRING-B.edge5.Amsterdam1.Level3.net [212.72.41.142]
14    44 ms    44 ms    44 ms  po100.hv1.evo.leaseweb.net [85.17.100.222]
15    54 ms    51 ms    54 ms  www.filefactory.com [85.17.172.100]
Trace complete.

[#12]

20CN  8Mb ADSL  pcl-ag03  MTU=1430

$ mtr filefactory.com
HOST: my_desktop                  Loss%   Snt   Last   Avg  Best  Wrst StDev
  1. my_gateway                   75.0%   100    3.7   4.2   3.0   7.5   1.3
  2. lo0-central1.pcl-ag03.plus.n 18.0%   100   29.1  28.4  22.9 151.4  14.9
  3. gi1-9-312.pcl-gw02.plus.net   6.0%   100   32.8  44.5  31.4 245.8  38.9
  4. tun0.pcl-gw01.plus.net       32.0%   100   33.5  38.1  31.6 218.1  24.9
  5. flowers2.servers.plus.net.uk 52.0%   100   35.0  33.1  31.2  38.4   1.5
  6. xe-11-1-0.edge3.London2.Leve 13.0%   100   33.0  33.8  31.5  72.1   4.6
  7. ae-0-11.edge4.London2.Level3 25.0%   100   32.0  36.2  30.8  85.6  10.1
  8. ae-3-3.ebr1.London1.Level3.n 60.0%   100   33.9  33.5  31.7  38.6   1.4
  9. vlan103.ebr2.London1.Level3. 14.0%   100   32.7  33.4  31.7  37.6   1.1
 10. ae-48-48.ebr2.Amsterdam1.Lev 13.0%   100   40.1  40.8  39.2  46.0   1.2
 11. ae-57-222.csw2.Amsterdam1.Le 57.0%   100   51.1  43.0  39.3  51.6   4.0
 12. 4.69.162.158                 29.0%   100   39.5  41.0  39.2  62.6   2.9
 13. LEASEWEB.edge5.Amsterdam1.Le  9.0%   100   45.8  44.9  40.3  50.3   2.5
 14. po100.hv1.evo.leaseweb.net   58.0%   100   45.2  46.0  40.1 222.3  27.9
 15. 85.17.172.100                31.0%   100   47.0  46.7  34.1  54.9   5.0

$ mtr plus.net
HOST: my_desktop                  Loss%   Snt   Last   Avg  Best  Wrst StDev
  1. my_gateway                    0.0%   100    3.1   4.0   2.9   8.9   1.3
  2. lo0-central1.pcl-ag03.plus.n  0.0%   100   34.4  30.2  22.9  81.9  11.0
  3. gi1-9-312.pcl-gw02.plus.net   0.0%   100   33.2  53.5  25.8 303.0  52.0
  4. po4.pcl-gw01.plus.net         0.0%   100   40.3  50.5  39.0 268.6  34.8
  5. gi5-8.ptp-cr01.plus.net       0.0%   100   40.6  40.9  38.9  50.1   1.7
  6. vlan2658.ptp-elb02.plus.net   0.0%   100   40.7  42.8  33.4  78.4   4.5
  7. portal.plus.net               0.0%   100   40.1  41.8  39.3  54.2   1.8

[#13]

Well, according to "traceroute --mtu", the mtu is restricted to 1476 somewhere inside plusnet's network, but setting my computer's mtu to 1430, 1400 or even 500 does not solve the problem.
[tt]traceroute --mtu www.filefactory.com
traceroute to www.filefactory.com (85.17.172.100), 30 hops max, 65000 byte packets
1  192.168.0.1 (192.168.0.1)  2.452 ms F=1500  2.328 ms  3.564 ms
2  lo0-central5.ptn-ag04.plus.net (195.166.130.83)  52.777 ms  51.996 ms  49.500 ms
3  84.93.253.83 (84.93.253.83)  48.470 ms  48.974 ms  48.639 ms
4  po4.ptn-gw01.plus.net (212.159.1.138)  48.402 ms  48.842 ms  48.219 ms
5  tun0.ptn-gw01.plus.net (212.159.2.101)  47.488 ms F=1476  46.969 ms  47.366 ms
6  195.99.126.144 (195.99.126.144)  48.256 ms  47.630 ms  47.347 ms
7  ten4-0.lon.leaseweb.net (195.66.225.56)  58.583 ms  55.355 ms  54.402 ms
8  po100.hv1.evo.leaseweb.net (85.17.100.222)  70.224 ms  55.675 ms  55.753 ms
9  85.17.172.100 (85.17.172.100)  62.810 ms  58.319 ms  61.287 ms[/tt]
[tt]ping -s 1448 www.filefactory.com
PING www-origin.filefactory.com (85.17.172.100) 1448(1476) bytes of data.
1456 bytes from 85.17.172.100: icmp_req=1 ttl=57 time=60.6 ms
1456 bytes from 85.17.172.100: icmp_req=2 ttl=57 time=62.9 ms
1456 bytes from 85.17.172.100: icmp_req=3 ttl=57 time=61.5 ms
1456 bytes from 85.17.172.100: icmp_req=4 ttl=57 time=67.2 ms
--- www-origin.filefactory.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 60.674/63.103/67.299/2.570 ms
ping -s 1449 www.filefactory.com
PING www-origin.filefactory.com (85.17.172.100) 1449(1477) bytes of data.
From po4.ptn-gw01.plus.net (212.159.1.138) icmp_seq=1 Frag needed and DF set (mtu = 1476)
--- www-origin.filefactory.com ping statistics ---
7 packets transmitted, 0 received, +1 errors, 100% packet loss, time 6001ms[/tt]
Also, 195.99.126.144 is going via BT rather than Level 3.

[#14]

This morning I also had difficulties with this gateway: lo0-central2.pcl-ag02.plus.net
Sites timing out, including all Hurricane Electric domains (www.he.net is the main one) and http://ipv6-test.com/
Forgot to check FileFactory at the time (not with it at mo with this nasty cold).

[#15]

RPM, Are you still having trouble with www.he.net ? I'm on pcl-ag02 (20CN) lo0-central3.pcl-ag02.plus.net [195.166.128.237] and got there ok.
also
Tracing route to he.net [216.218.186.2]
over a maximum of 30 hops:
  1    1 ms    <1 ms    1 ms  RTA1335.home [192.168.1.1]
  2    36 ms    47 ms    36 ms  lo0-central3.pcl-ag02.plus.net [195.166.128.237]
  3  151 ms    83 ms  219 ms  gi1-23-232.pcl-gw02.plus.net [84.92.6.50]
  4    35 ms    35 ms    33 ms  ae3.pcl-cr02.plus.net [195.166.129.42]
  5    37 ms    34 ms    51 ms  ae1.ptw-cr02.plus.net [195.166.129.2]
  6    33 ms    34 ms    34 ms  po2.ptw-gw02.plus.net [195.166.129.39]
  7    40 ms    37 ms    36 ms  10gigabitethernet1-1.core1.lon1.he.net [195.66.224.21]
  8  110 ms  104 ms  104 ms  10gigabitethernet7-4.core1.nyc4.he.net [72.52.92.241]
  9  172 ms  174 ms  174 ms  10gigabitethernet10-2.core1.sjc2.he.net [184.105.213.197]
10  219 ms  172 ms  176 ms  10gigabitethernet1-1.core1.fmt1.he.net [72.52.92.109]
11  172 ms  174 ms  173 ms  www.he.net [216.218.186.2]
Trace complete.
Another try
Tracing route to he.net [216.218.186.2]
over a maximum of 30 hops:
  1    <1 ms    1 ms    <1 ms  RTA1335.home [192.168.1.1]
  2    38 ms    41 ms    37 ms  lo0-central3.pcl-ag02.plus.net [195.166.128.237]
  3    34 ms    35 ms    36 ms  gi1-23-232.pcl-gw02.plus.net [84.92.6.50]
  4    39 ms  514 ms    36 ms  ae3.pcl-cr02.plus.net [195.166.129.42]
  5    45 ms    34 ms    46 ms  ae1.ptw-cr02.plus.net [195.166.129.2]
  6    36 ms    34 ms    34 ms  po2.ptw-gw02.plus.net [195.166.129.39]
  7    33 ms    35 ms    33 ms  10gigabitethernet1-1.core1.lon1.he.net [195.66.224.21]
  8  105 ms  104 ms  113 ms  10gigabitethernet7-4.core1.nyc4.he.net [72.52.92.241]
  9  172 ms  174 ms  174 ms  10gigabitethernet10-2.core1.sjc2.he.net [184.105.213.197]
10  178 ms  176 ms  176 ms  10gigabitethernet1-1.core1.fmt1.he.net [72.52.92.109]
11  172 ms  175 ms  174 ms  www.he.net [216.218.186.2]
Trace complete.