Diagnosing a BT BB issue

lphchild

Hi,

I'm on BT having recently been upgraded to 8MB on the Summerhill exchange. Up until now I haven't had any connection issues. However now, every few minutes, my connection is giving me problems, sites become unreachable, not just from my machine but from another on the network as well.

My router says the connection is fine and I can connect to it fine internally during these blips.

After a few refreshes the site come in properly.

Is there anything I can do to try and diagnose the problem further, to try and identify the cause?

lph

jor el

Could be a DNS issue. I had been seeing some bad DNS problems with BT before leaving them (not on LLU though) and I changed to OpenDNS. Google for settings. Try that first anyway and see if it improves.

lphchild

Cheers, for that, I'm using OpenDNS already - it's strange problem and totally annoying at this stage!

dub45

Have you checked your line stats since you changed speed?

BlackWizard

I couldn't access boards.ie for about an hour. Just got on now.

The laptops in the house are having awful problems with DNS and having to repair the connection in windows quite often. Had to do it on the PC a few times too.

I don't think it's on my end. I can't even use the IP address of boards.ie to access it in a browser. I can ping boards.ie fine at the time of not being able to access it.

Yesterday, all my torrents stopped working altogether. Taking a 5 gig file from college and suddenly it stopped. Now no trackers seem to be working. They are all "offline" despite them actually being online.

Weirdness

Oh yeah im with BT. 2mb connection on the Palmerstown exchange which apparently is being upgraded "soon"

Edit: Everything is back up working again, but it usually doesn't last more than a few hours or days at most.

lphchild

Yeh, line stats look fine to me:

Connection Speed 8123 kbps 508 kbps
Line Attenuation 12 db 2.5 db
Noise Margin 25 db 25 db

When it try tracert to boards by IP during a 'blip' I get results like this:

tracert 89.234.66.107

Tracing route to 89.234.66.107 over a maximum of 30 hops

1 1 ms 1 ms 1 ms www.routerlogin.com [192.168.0.1]
2 22 ms 21 ms 22 ms bas508.cwt.esat.net [193.95.136.245]
3 23 ms 22 ms 23 ms 193.95.137.124
4 23 ms 22 ms 22 ms 193.95.130.137
5 23 ms 23 ms 23 ms 193.95.129.4
6 22 ms 24 ms 23 ms 193.242.111.20
7 25 ms 25 ms 26 ms 89.234.66.107

Trace complete.

Another example - get's so far into the route then stops being able to resolve host names again:
Tracing route to 89.234.66.107 over a maximum of 30 hops

1 1 ms 1 ms 1 ms www.routerlogin.com [192.168.0.1]
2 22 ms 23 ms 23 ms bas508.cwt.esat.net [193.95.136.245]
3 23 ms 22 ms 22 ms vlan501.rt501.cwt.esat.net [193.95.137.124]
4 24 ms 23 ms 22 ms vlan51.rt001.cwt.esat.net [193.95.130.137]
5 23 ms 23 ms 22 ms ge0-0.br001.cwt.esat.net [193.95.129.4]
6 23 ms 22 ms 23 ms 193.242.111.20
7 26 ms 26 ms 25 ms 89.234.66.107


and

ping www.boards.ie
Ping request could not find host www.boards.ie. Please check the name and try again.

So I'm using OpenDNS - which isn't reporting any problem, same thing happens as above using BT DNS servers. Can anyone interpret the tracert results - look to me like it's loosing the ability to resolve the various host names... Help?

CptSternn

How fast is your PC? I have seen this happen on older PCs - they can't handle the traffic. In fact, when using bit torrent on a P4/1gig machine with 512k RAM I have seen it bring the machine to a crawl. When we adjusted the number of simultaneous connections it kept the machine from slowing to a crawl, but then the connection would still cut off sporadically as the machine still couldn't handle all the data coming down the pipe. We eventually got it leveled off by limiting the maximum download speed.

Have you tried another PC? You might want to bring in a friends new laptop with a nice fat processor and a couple gigs of RAM and see if the problem persists.

Also, have you played with the MTUs on the router? I have seen some people who drop back to 1400 (from 1500 or 1432) fix this issue as well.

Then there is also the router itself - are you using the one BT gave you? I have seen strange problems with people who purchased their own routers, sometimes they just aren't compatible with your ISP.

lphchild

Thanks for the reply..

I'm running 2gig machine core duo, so the machine shouldn't be an issue. I've also replicated the issue on my mac and another vista laptop.

I'm using a Netgear DG834G which up until now hasn't had any problems at all. After the upgrade it was fine, the problem has started occurring this week :-(

I'll try dropping back MTU and see if that makes a difference...

BlackWizard

These are my tracert and ping results. Right now the internet is acting odd. If I open up a new tab, it sometimes wont load any new pages. Same is on the second PC and the laptop on the wireless. Torrents won't connect to the trackers either.

Tracing route to www.boards.ie [89.234.66.107]
over a maximum of 30 hops:

1 1 ms 1 ms <1 ms www.routerlogin.com [192.168.0.1]
2 30 ms 12 ms 12 ms bas508.cwt.esat.net [193.95.136.245]
3 561 ms 577 ms 437 ms vlan501.rt502.cwt.esat.net [193.95.137.125]
4 409 ms 317 ms 586 ms vlan52.rt001.cwt.esat.net [193.95.130.145]
5 588 ms 596 ms 588 ms 193.95.129.4
6 582 ms 397 ms 305 ms 193.242.111.20
7 371 ms 566 ms 400 ms 89.234.66.107

Trace complete.

Tracing route to www.boards.ie [89.234.66.107]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms www.routerlogin.com [192.168.0.1]
2 568 ms 578 ms 446 ms bas508.cwt.esat.net [193.95.136.245]
3 570 ms 534 ms 661 ms vlan501.rt502.cwt.esat.net [193.95.137.125]
4 432 ms 465 ms 752 ms vlan52.rt001.cwt.esat.net [193.95.130.145]
5 277 ms 282 ms 72 ms ge0-0.br001.cwt.esat.net [193.95.129.4]
6 278 ms 278 ms 260 ms to-inex-dub-deg-gw.digiweb.ie [193.242.111.20]
7 283 ms 290 ms 283 ms 89.234.66.107

Trace complete.

Tracing route to 89.234.66.107 over a maximum of 30 hops

1 1 ms 1 ms <1 ms www.routerlogin.com [192.168.0.1]
2 281 ms 278 ms 275 ms bas508.cwt.esat.net [193.95.136.245]
3 275 ms 282 ms 277 ms vlan501.rt502.cwt.esat.net [193.95.137.125]
4 284 ms 295 ms 276 ms vlan52.rt001.cwt.esat.net [193.95.130.145]
5 278 ms 276 ms 275 ms ge0-0.br001.cwt.esat.net [193.95.129.4]
6 279 ms 289 ms 264 ms to-inex-dub-deg-gw.digiweb.ie [193.242.111.20]
7 275 ms 277 ms 289 ms 89.234.66.107

Trace complete.

Pinging www.boards.ie [89.234.66.107] with 32 bytes of data:

Reply from 89.234.66.107: bytes=32 time=272ms TTL=57
Reply from 89.234.66.107: bytes=32 time=108ms TTL=57
Reply from 89.234.66.107: bytes=32 time=283ms TTL=57
Reply from 89.234.66.107: bytes=32 time=284ms TTL=57

Ping statistics for 89.234.66.107:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 108ms, Maximum = 284ms, Average = 236ms

Router Stats

ADSL Link

Downstream

Upstream

Connection Speed

2048 kbps

256 kbps

Line Attenuation

18 db

6.5 db

Noise Margin

23 db

19 db

I think we might be having to different issues Thought we could get two birds with the one stone here.

Although on some of my steps like
5 588 ms 596 ms 588 ms 193.95.129.4
6 582 ms 397 ms 305 ms 193.242.111.20
7 371 ms 566 ms 400 ms 89.234.66.107

seem to be using just the IP and don't seem to return the URL like
5 277 ms 282 ms 72 ms ge0-0.br001.cwt.esat.net [193.95.129.4]
6 278 ms 278 ms 260 ms to-inex-dub-deg-gw.digiweb.ie [193.242.111.20]
7 283 ms 290 ms 283 ms 89.234.66.107

lphchild

I don't think we're that far removed - the failure to ping is intermittent - depends on how quickly you catch it...the traces look very similar though... I changed the MTU but it made no difference...

Furp

I am also having strange issues at the moment and I am on BT.

If I open a new tab even just google i somtimes it loads straight away other times it will take 10-20 seconds, if I open an additional tab to boards it comes up straight away although the redirecter after log in does not work i have to click the link.

I am also using opendns. This is interesting though look at these pings.

ping boards.ie

Pinging boards.ie [89.234.66.107] with 32 bytes of data:

Reply from 89.234.66.107: bytes=32 time=22ms TTL=57
Reply from 89.234.66.107: bytes=32 time=22ms TTL=57
Reply from 89.234.66.107: bytes=32 time=23ms TTL=57
Reply from 89.234.66.107: bytes=32 time=23ms TTL=57

Ping statistics for 89.234.66.107:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 22ms, Maximum = 23ms, Average = 22ms


ping www.google.ie

Pinging google.navigation.opendns.com [208.69.34.230] with 32 bytes of data:

Reply from 208.69.34.230: bytes=32 time=94ms TTL=53
Reply from 208.69.34.230: bytes=32 time=46ms TTL=53
Reply from 208.69.34.230: bytes=32 time=49ms TTL=53
Reply from 208.69.34.230: bytes=32 time=47ms TTL=53

Ping statistics for 208.69.34.230:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 46ms, Maximum = 94ms, Average = 59ms

ping www.google.com

Pinging google.navigation.opendns.com [208.69.34.231] with 32 bytes of data:

Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 208.69.34.231:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

So when I ping google.com it timesout when I ping google.ie its ok, yet when I ping google.com it goes to a differant opendns server.

I presume this means that its a problem with Opendns server google.navigation.opendns.com [208.69.34.231]

lphchild

BlackWizard are you using OpenDNS?

Saw your post furp on OpenDNS hopefully they can shed some light on it...

BlackWizard

I don't use OpenDNS

I'll double check the router in a min. But I never set it up,

EDIT:

I don't have OpenDNS configured. It uses the ISP DNS.

I seen furps post also. Hopefully something will come of this

lphchild

I've gone back to BT's DNS and it seems to be better - I think it may be OpenDNS - I'll give it a couple of days back on BT then try OpenDNS... just in case anyone's doing the same - after changing back to BT remember to flush DNS on your local machine.

ipconfig /flushdns

Cheers