DNS problems

Hi all.

As soon as I start using uTorrent, my DNS service stops working and I can no longer browse sites on the Internet. The Internet connection itself works of course since I can download without any problems. I have configured port forwarding in my router so the status is green, both upload and download is working fine, but the only problem is that everything else that uses the Internet connection stops, and I believe I've pinpointed it to the URL name resolution, it seems it's impossible to connect to my ISPs DNS-servers as soon as I start uTorrent.

The thing is, I've experienced the exact same issue many years ago, on a different ISP, different computer etc, and the solution then was to decrease the number of active connection in my torrent client. I've tried that and still it doesn't work.

Searched the forums and FAQ but didn't find anything.

Thanks for your help,

D.

___

uTorrent 2.0, W7 x64.

1st and 2nd links in my signature.

Thanks Switeck, I'll try those and post my results.

I have the exactly same problem. I can get out on the internet from other computers in the network, through the router. But not from the pc I have my utorrent client.

I would very much like to hear if someone else have had this and found a solution !!

Cheers

1st and 2nd links in my signature.

[hr /]1st:Have you tried Ultima's Troubleshooting Guide?: http://forum.utorrent.com/viewtopic.php?id=15992

2nd:Recommended uTorrent settings: http://forum.utorrent.com/viewtopic.php?id=58404

Hi,

I've followed your advice Switeck, including the conservative settings (reducing connections etc) but it didn't help. I even tried disabling the resolve IP-setting for peers. Like I tried to explain, my problem is not with the torrent download/upload ability, speed etc itself because those things run fine. It's just as soon as I start uTorrent, it's like my computer loses it's connection to my ISPs DNS - and just like Tigerola wrote, I can still surf the Web etc from my other PCs on the same network, so _something_in_uTorrent kills the DNS-lookup abilities of my PC. That means I can either surf the Web, or uTorrent - never both those things at the same time, and it's a bit bad.

Any other ideas?

Did you try disabling UPnP, NAT-PMP, DHT (both kinds), LPD, uTP (Bandwidth Management), and maybe even Teredo itself?

Thanks for your suggestions, Switeck.

I have now disabled the following settings, under these sections:

Connection

-Enable UpnP port mapping

-Enable NAT-PMP port mapping

BitTorrent

-Enable DHT Network

-Enable DHT for new torrents

-Enable Local Peer Discovery

-Enable bandwidth management

And that Teredo thing, I think it's disabled by default because I could only find one setting for it, under General, I have a button in the Windows Integration section that says "Install IPv6/Teredo" with the Windows icon, which I guess implies that it's not activated?

Also I wonder what downsides/cons there are with your suggestions, will I lose performance, speed etc with those settings disabled?

I'll do som testing and let you know how it went.

Thanks.

UPnP and NAT-PMP are auto port forwarding...that sometimes cause more problems.

DHT doesn't work with private torrents/trackers. It's also not needed for torrents whose trackers never go offline.

Local Peer Discovery tries to find "nearby" peers/seeds on the same portion of the same ISP as you. These can be found in other ways, so this may be redundant.

Bandwidth Management is uTP.

I've got exact same problem as OP. These DNS problems started when I updated my utorrent to newest (2.10) version.

Try disabling uTP then.

By the way Switeck, you can't uninstall IPv6 or Teredo anymore. But you can disable 6to4 and Teredo (disabling Teredo alone isn't enough).

Hi,

so the results are in, and the problem still exist

All those things I disabled didn't help... this is so frustrating, and since there are others having the exact same issue, we should be able to find out the root cause.

My cablemodem/wireless router is Netgear CG3100 and my ISP is comhem (one of Sweden's largest ISPs).

What more can I try doing?

Is it disabling Teredo and 6to4, and where can I find those settings considering Firon's post.

Can't you get a modem that's only a modem, not a modem/router combo?

netsh int 6to4 set state disable

netsh int teredo set state disable

I thought I'd give you an update.

I upgraded to uT 2.0.2 and by the first attempt, my issue with DNS/unability to surf while uT is running seems gone! Can others that reported the same issue as I please try upgrading and see if they experience the same resolution to this issue?

If this in fact was an issue in uT and it's solved between 2.0.0 and 2.0.2, the developers might be interested in knowing this I guess.

Thanks!

I had the exact same problem as the OP and recently upgraded to 2.0.2 and it has improved but it is far from resolved.

Before upgrade 99% of my DNS lookups failed and now about 90% of them fail.

The funny part is that not even one torrent is runnig. I stopped them all but I just need to start uTorrent to halt my DNS lookups. If I close uTorrent again everything is back to normal within a minute.

Some lookups and finally a ping to my DNS to show that it alwyas responds to ping

C:\Users\Calle>nslookup www.google.com

DNS request timed out.

timeout was 2 seconds.

Server: UnKnown

Address: 83.255.245.11

Icke-auktoritärt svar:

DNS request timed out.

timeout was 2 seconds.

Namn: www.l.google.com

Addresses: 74.125.77.147

74.125.77.99

74.125.77.104

Aliases: www.google.com

C:\Users\Calle>nslookup www.google.com

Server: resolver1.comhem.se

Address: 83.255.245.11

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

*** Begäran till resolver1.comhem.se orsakade timeout

C:\Users\Calle>nslookup www.google.com

DNS request timed out.

timeout was 2 seconds.

Server: UnKnown

Address: 83.255.245.11

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

*** Begäran till UnKnown orsakade timeout

C:\Users\Calle>nslookup www.google.com

DNS request timed out.

timeout was 2 seconds.

Server: UnKnown

Address: 83.255.245.11

DNS request timed out.

timeout was 2 seconds.

Icke-auktoritärt svar:

Namn: www.l.google.com

Addresses: 74.125.77.99

74.125.77.104

74.125.77.147

Aliases: www.google.com

C:\Users\Calle>ping 83.255.245.11

Skickar ping-signal till 83.255.245.11 med 32 byte data:

Svar från 83.255.245.11: byte=32 tid=9ms TTL=124

Svar från 83.255.245.11: byte=32 tid=8ms TTL=124

Svar från 83.255.245.11: byte=32 tid=8ms TTL=124

Svar från 83.255.245.11: byte=32 tid=8ms TTL=124

Ping-statistik för 83.255.245.11:

Paket: Skickade = 4, Mottagna = 4, Förlorade = 0 (0 %),

Ungefärlig överföringstid i millisekunder:

Lägsta = 8 ms, Högsta = 9 ms, Medel = 8 ms

I've had this problem before but its been a while. I would lose all dns and therefore http transfer and trackers. Torrents would still continue but I couldn't browse until I restarted. It seemed fairly random when this would happen and then one day it stopped. never did figure out why.

"I would lose all dns and therefore http transfer and trackers."

Sounds like a partial router crash...or bombed software firewall.

Maybe it was a software firewall and a later update fixed that problem?

hobox72,

Is DHT running in uTorrent?

Is UPnP and/or NAT-PMP enabled in uTorrent?

Is Local Peer Discovery enabled?

DHT is not running

UPnP NAT-PMP tried both enabled and disabled. Same thing.

Local Peer discovery enabled.

Exception in Windows Firewall same thing if enabled or disabled

I use the same port 24201 all the time and has it forwarded in my router. But on another Windows 7 64 bit machine I use random port and no forwarding and have the exact same issue.

I doubt it's a firewall, I never use a third-party one and actually completely disable windows firewall, it gets in the way. As far as hardware its been a while since I had the problem but i remember it happening with both setups i've run. Only modem (speedstream) and modem into router (modem running as bridge). I've still got the same router and I didn't change utorrent versions when it got fixed. All i remember is that it was only that one computer that stopped working, the rest in the network continued just fine. A restart of the computer would repair the problem but restarting utorrent would not.

I wonder if maybe its a function of the isp's dns servers. A kind of time out that blocks all requests from specific mac addresses if it gets to many over a certain period of time. Try using a public dns server as opposed to the one your isp gave you and see if that helps. An overload makes sense in this situation, its just a matter of finding out where it is.

Public DNS doesn't work. Tried it already.

If you do a "nslookup www.domain.com NS-server" it doesn't matter if you never even used the NS-server before. Most calls just times out.

C:\Users\Calle>nslookup www.google.com

DNS request timed out.

timeout was 2 seconds.

Server: UnKnown

Address: 83.255.245.11

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

*** Begäran till UnKnown orsakade timeout

C:\Users\Calle>nslookup www.google.com 8.8.8.8

DNS request timed out.

timeout was 2 seconds.

Server: UnKnown

Address: 8.8.8.8

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

*** Begäran till UnKnown orsakade timeout

C:\Users\Calle>nslookup www.google.com 8.8.4.4

DNS request timed out.

timeout was 2 seconds.

Server: UnKnown

Address: 8.8.4.4

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

*** Begäran till UnKnown orsakade timeout

C:\Users\Calle>nslookup www.google.com 67.138.54.100

DNS request timed out.

timeout was 2 seconds.

Server: UnKnown

Address: 67.138.54.100

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

DNS request timed out.

timeout was 2 seconds.

*** Begäran till UnKnown orsakade timeout

I don't belive it is an overload. Because ALL torrents are switched off.I don't seed and I don't leech. I just started utorrent and after about 20 secs DNS wont work. Likewise it takes about 20 secs after utorrent is closed down for everything to start work again.

hobox72,

Is IPv6 present? (Teredo/IPv6 and/or native IPv6?)

Are you getting lots of incoming connections? (possibly for now-stopped torrents?)

How do I check that?

uTorrent's Logger window/tab at bottom left should tell about incoming connections.

Just right-click in the window to enable logging!

As for Teredo/IPv6, does uTorrent show in logger about it being enabled/available at uTorrent start-up?

Ok. Here is my log for about 20 secs

[2010-07-19 19:47:24] *** Starting Diagnostic thread ***

[2010-07-19 19:47:24] IPv6 is installed

[2010-07-19 19:47:24] Got Teredo Address: 2001:0:5ef5:73ba:3031:3f6:af26:7853

[2010-07-19 19:47:24] Incoming connection from [2001:0:5ef5:73bc:1876:272a:adf3:233c]:13254

[2010-07-19 19:47:25] Incoming connection from 82.12.220.195:13254

[2010-07-19 19:47:25] Incoming connection from 78.105.197.215:59502

[2010-07-19 19:47:25] Incoming connection from 75.172.115.101:12485

[2010-07-19 19:47:26] Incoming connection from 192.168.0.10:24201

[2010-07-19 19:47:26] Incoming connection from 192.168.0.10:49440

[2010-07-19 19:47:26] Incoming connection from 80.217.135.172:24201

[2010-07-19 19:47:26] Incoming connection from 80.217.135.172:49441

[2010-07-19 19:47:27] Incoming connection from 75.172.115.101:12485

[2010-07-19 19:47:29] Incoming connection from 203.219.232.54:28842

[2010-07-19 19:47:30] Incoming connection from 203.219.232.54:60257

[2010-07-19 19:47:36] Incoming connection from 66.129.224.36:12781

[2010-07-19 19:47:36] Incoming connection from 66.129.224.36:34420

[2010-07-19 19:47:37] Incoming connection from 59.167.171.226:16787

[2010-07-19 19:47:43] Incoming connection from 78.105.197.215:50063

I would say Teredo is present and used!

[2010-07-19 19:47:24] IPv6 is installed

[2010-07-19 19:47:24] Got Teredo Address: 2001:0:5ef5:73ba:3031:3f6:af26:7853

[2010-07-19 19:47:24] Incoming connection from [2001:0:5ef5:73bc:1876:272a:adf3:233c]:13254

Strange...a LAN ip?:

[2010-07-19 19:47:26] Incoming connection from 192.168.0.10:24201

[2010-07-19 19:47:26] Incoming connection from 192.168.0.10:49440

Are there other BitTorrent clients running on your LAN?

There's definitely some activity from incoming connections...though that's nowhere near enough to cause a problem except for absolutely terrible networking software and hardware.