PDA

View Full Version : Browsing drop-outs to certain sites only. Download OK.


CalmEddie
21-01-2010, 14:11
Hi! This looks like a great site. I've had an intermittent problem with my connection for over a year now. Because it's intermittent it's been so hard to diagnose, but now it's becoming more frequent. Sorry for the long post...


I have a VirginMedia 20Mbit connection (used to be NTL) with an VM branded Ambit 256 modem.
Connected to this via the WAN port is a Netgear blue-box wireless router: FWG114P with latest firmware version 2.0_18.
The router is configured to use openDNS, and shares these settings with the LAN using DHCP.

The LAN consists of:
1x Ubuntu 8.04 server.
1x Ubuntu 9.10 64bit high spec workstation client. Contains a number of virtual machines inc xin XP
1x Mac Mini client running dual boot Mac OS leapard and Ubuntu 9.10
1x Sony Vaio laptop client running dual boot windows XP and Ubuntu 9.10
1x NAS Storage
1x Netgear GS108 Switch
1x Playstation 3
None of the clients have firewalls, they rely on the NAT router. Obviously none of the linux machines have anti-virus software.

The cable modem and router are remote, located in a crawlspace in the loft next to the server / NAS. They are in this location to keep the noise down from the server. I switch them on/off using a remote device
Like this one: http://www.keene.co.uk/electronics/multi.php?mycode=RCS3
I can go and see the lights, but usually this is not practical enough to give valuable info while browsing.

I am experiencing web browsing dropouts. There are very strange, and appear to be consistent with cache / proxy problems at VM.

When there is a dropout, certain sites are unreachable. Others are perfectly reachable. The behaviour is consistent across all clients, and contacting friends at these times, they confirm the sites are not down.
Downloads are unaffected, but browsing is painful.

I can't see how any of my local equipment would arise a situation like this. IME, LAN either works or it doesn't and won't give strange routing problems like blocking certain web sites.

Power-cycling modem + router sometimes give an improvement which will last half a day. If I contact VM customer services, they reset the modem remotely and this makes a huge improvement. Browsing becomes faultless and much faster than usual, but this only lasts a week at most.

Swapping over to a direct ethernet connection to a single machine (the sony laptop in the crawlspace), the problem seems to go away. However, the problem also goes away if I power-cycle the modem. So this might be influencing this test.

But this means I still end up dis-trusting my set-up. Today I took the router back to factory settings, and re-uploaded the firmware. I've left it on vanilla settings as far as possible, but it's made no difference.

I've reset and rebuilt everything on the LAN. I've been over and over all the settings, used a tester on all the LAN cables. Swapped out LAN cables anyway.
Any help greatly appreciated.

I'm just starting to do ping and traceroute tests. Please bear with me as I have to mess about in the crawl-space to get the direct results. I will post back with values soon.

---------- Post added at 13:11 ---------- Previous post was at 12:26 ----------

The info here is 4 years old...,
http://www.cableforum.co.uk/board/12/26006-cable-modem-signal-levels.html
but I assume is still current. :) I should expect:
Downstream Receive Power Level: Ideally -6dBmV to +15dBmV
Downstream SNR: Minimum is 33dB.
Upstream Transmit Power: Anything between 28dB and 53dB is fine.

I'm getting:
Downstream Receive Power Level : 5.9 dBmV
Downstream SNR : 40.5 dB
Upstream transmit Power Level : 40.5 dBmV

Which seems OK.

Sephiroth
21-01-2010, 14:54
Not my bag, especially with non-Windows machines.

But recently when something akin to this came up either here or in the VM forum, the solution was to put webcache.virginmedia.com (I think) as the proxy on port 8080. Whether or not this opens up other problems (like old pages), I can't say.

Have you searched the forum on OpenDNS? The one I had in mind was within the last week.

CalmEddie
21-01-2010, 17:03
I'll try the openDNS forums too, thanks. On a related note, the results are the same for me with/without opendns.

I don't think we need worry about the clients being linux. It seems very unlikely it's a client machine issue. I thought it was relevant and many of the good suggestions on here involve running windows diagnostic tools. I should be able to find equivalents.

Here are the ping / traceroute figures.
Ping and traceroutes. www.therevcounter is a site which is particularly unreliable for me. Other members of this site have no problems.
My IP has been replaced with xx.xx.xx.xx

ping test script on Ubuntu workstation - via router
--------------------------------------------------------------------------------
Pinging each of these sites, with a count of 4 :
www.google.co.uk www.bbc.co.uk www.therevcounter.com
--------------------------------------------------------------------------------
www.l.google.com Average time: 33.080 Packet loss: 0%
www.bbc.net.uk Average time: 20.110 Packet loss: 0%
www.therevcounter.com Average time: 33.744 Packet loss: 0%



traceroute on Ubuntu workstation - via router

traceroute to www.therevcounter.com (217.160.6.247), 30 hops max, 60 byte packets
1 cpc3-warw12-2-0-gw.3-2.cable.virginmedia.com (xx.xx.xx.xx) 12.001 ms 12.379 ms 12.748 ms
2 brhm-core-1a-ge-300-2188.network.virginmedia.net (213.105.103.201) 13.109 ms 13.478 ms 14.244 ms
3 bir-bb-a-ae1-0.network.virginmedia.net (213.105.103.97) 13.841 ms 16.872 ms 17.247 ms
4 nth-bb-b-ae2-0.network.virginmedia.net (62.253.185.85) 23.342 ms 22.956 ms 23.706 ms
5 tele-ic-1-as0-0.network.virginmedia.net (62.253.184.2) 25.069 ms 25.444 ms 28.471 ms
6 linx.bb-c.the.lon.gb.oneandone.net (195.66.224.98) 28.853 ms 20.697 ms 21.030 ms
7 te-1-3.bb-c.bap.rhr.de.oneandone.net (212.227.120.49) 35.106 ms 35.130 ms 35.483 ms
8 te-4-1.bb-c.bs.kae.de.oneandone.net (212.227.121.167) 34.703 ms 34.394 ms 34.760 ms
9 ae-6.gw-distp-a.fs.kae.de.oneandone.net (212.227.116.225) 35.123 ms 35.492 ms 34.250 ms
10 ae-1.gw-prtr-r1-1a.fs.kae.de.oneandone.net (195.20.247.199) 34.843 ms * *
11 s15344005.onlinehome-server.info (217.160.6.247) 34.826 ms 38.200 ms 34.409 ms

#####################################
ping test script on Ubuntu server - via router
--------------------------------------------------------------------------------
Pinging each of these sites, with a count of 4 :
www.google.co.uk www.bbc.co.uk www.therevcounter.com
--------------------------------------------------------------------------------
www.l.google.com Average time: 33.291 Packet loss: 0%
www.bbc.net.uk Average time: 20.243 Packet loss: 0%
www.therevcounter.com Average time: 33.839 Packet loss: 0%


traceroute on Ubuntu server - via router

traceroute to www.therevcounter.com (217.160.6.247), 30 hops max, 60 byte packets
1 cpc3-warw12-2-0-gw.3-2.cable.virginmedia.com (xx.xx.xx.xx) 10.714 ms 11.017 ms 13.245 ms
2 brhm-core-1a-ge-300-2188.network.virginmedia.net (213.105.103.201) 13.883 ms 14.262 ms 14.631 ms
3 bir-bb-a-ae1-0.network.virginmedia.net (213.105.103.97) 14.994 ms 15.734 ms 15.352 ms
4 nth-bb-b-ae2-0.network.virginmedia.net (62.253.185.85) 24.395 ms 23.992 ms 24.761 ms
5 tele-ic-1-as0-0.network.virginmedia.net (62.253.184.2) 26.180 ms 26.566 ms 27.318 ms
6 linx.bb-c.the.lon.gb.oneandone.net (195.66.224.98) 26.930 ms 20.543 ms 20.858 ms
7 te-1-3.bb-c.bap.rhr.de.oneandone.net (212.227.120.49) 34.826 ms 34.721 ms 35.428 ms
8 te-4-1.bb-c.bs.kae.de.oneandone.net (212.227.121.167) 35.015 ms 36.087 ms 36.394 ms
9 ae-6.gw-distp-a.fs.kae.de.oneandone.net (212.227.116.225) 35.648 ms 35.263 ms 82.613 ms
10 ae-1.gw-prtr-r1-1a.fs.kae.de.oneandone.net (195.20.247.199) 83.285 ms 34.581 ms *
11 s15344005.onlinehome-server.info (217.160.6.247) 34.898 ms 36.504 ms *



################################################## ####################
ping test script on Ubuntu server - DIRECT ETHERNET CONNECTION

--------------------------------------------------------------------------------
Pinging each of these sites, with a count of 4 :
www.google.co.uk www.bbc.co.uk www.therevcounter.com
--------------------------------------------------------------------------------
www-tmmdi.l.google.com Average time: 29.964 Packet loss: 0%
www.bbc.net.uk Average time: 18.108 Packet loss: 0%
www.therevcounter.com Average time: 31.112 Packet loss: 0%

traceroute on Ubuntu server - DIRECT ETHERNET CONNECTION

traceroute to www.therevcounter.com (217.160.6.247), 30 hops max, 60 byte packets
1 cpc3-warw12-2-0-gw.3-2.cable.virginmedia.com (xx.xx.xx.xx) 6.968 ms 7.006 ms 10.818 ms
2 brhm-core-1a-ge-300-2187.network.virginmedia.net (213.105.103.197) 11.590 ms 11.875 ms 11.957 ms
3 bir-bb-a-ae1-0.network.virginmedia.net (213.105.103.97) 11.942 ms 11.946 ms 12.114 ms
4 nth-bb-b-ae2-0.network.virginmedia.net (62.253.185.85) 18.201 ms 18.266 ms 18.265 ms
5 tele-ic-1-as0-0.network.virginmedia.net (62.253.184.2) 20.863 ms 20.941 ms 20.940 ms
6 linx.bb-c.the.lon.gb.oneandone.net (195.66.224.98) 20.938 ms 15.991 ms 16.007 ms
7 te-1-3.bb-c.bap.rhr.de.oneandone.net (212.227.120.49) 34.145 ms 34.605 ms 34.505 ms
8 te-4-1.bb-c.bs.kae.de.oneandone.net (212.227.121.167) 33.647 ms 33.125 ms 33.203 ms
9 ae-6.gw-distp-a.fs.kae.de.oneandone.net (212.227.116.225) 33.643 ms 30.316 ms 30.332 ms
10 ae-1.gw-prtr-r1-1a.fs.kae.de.oneandone.net (195.20.247.199) 35.170 ms 34.277 ms 34.270 ms
11 s15344005.onlinehome-server.info (217.160.6.247) 33.724 ms 31.731 ms 31.944 ms

http://www.speedtest.bbmax.co.uk/
Results for speedtest #1264090464
Date of Speed Test: 2010-01-21 16:14:24
Download Speed: 19506 kbps (2438.3 KB/sec transfer rate)
Upload Speed: 724 kbps (90.5 KB/sec transfer rate)

CalmEddie
23-01-2010, 13:31
.... the solution was to put webcache.virginmedia.com (I think) as the proxy on port 8080.

Well, this works - so far so good anyway!! It seems to be doing the trick for a few days now.

I have previously searched for proxy info without luck, and when I brought this up with VM technical support on the phone they were adamant that they didn't use proxies.

Thank you Sephiroth!!