Dlink DIR-825 crases after uppgrade to 2.0.

[supergregg]

Hello!

I have a problem with the new version of uTorrent. Ever since I got the 2.0 version of uTorrent my Dlink 825 router with the latest firmware crashes when I download at high speed. With the old 1.8.5 version I can download at a comfortable speed of 10MB/s and all is well. But with the new uTorrent i have to cut the speed to under 2MB/s so that the router wont crash. I have a 100/13Mbit LAN FullDuplex internet connection. I have done the portforward and its set to TCP and UDP for a specific port.

Disabling the "Enable bandwidth management" has helped a bit but its still crashing the router, I have tried every setting there is a checkbox for, nothing helps exept lowering download speed.

I have tried the guides "Switeck" has in his signature but I don't think that setting the download speed lower is a solution. So the question is. What has changed so much in uT2.0 that the router cant handle the load any more?

[Switeck]

Tell us more about the settings in uTorrent you are using.

Did you disable DHT, Resolve IPs, UPnP, NAT-PMP, and Bandwidth Management?

...then restart uTorrent, to get clear results.

Your router may just be trash.

Have you tried disabling its Stateful Packet Inspection (SPI - sometimes called its firewall)?

[Pawnz0rz]

Revert to v1.8.5. This solved my problems almost immediately.

[rafi]

Revert to 2.01 beta and try those settings in advanced->:

net.utp_dynamic_packets_size = false

net.utp_initial_packets_size = 8

bt.connect_speed = 3

[supergregg]

I Disabled DHT, Resolve IP, UPNP,NAT-PMP, Bandwdth management and SPI firewall. Still the same problem. After a while the router just stops transferring packets.

My router might be crap but I was getting good speeds from it with earlier versions of uTorrent. Right up to the point where I was getting diskoverloads. And if you have any other router to recommend that can handle the 100mbit download speed without slowing down I'd be happy to know about it. As soon as I move I'll be building myself a FreeBSD based firewall. But for now I have to use the Dlink router.

I'm going to try rafi's settings and see what happens.

[rafi]

Just note, that in my experience - those settings are more likely to effect your upload and are sensitive to your UL limit . You might want to try with a few UL limits settings...

[supergregg]

Ok. I don't think the upload was ever a problem. Right now I just tested the Slackware linux torrent without any caps and when the transfer reached about 3MB/s down I could not surf the web from my computer. Upload was only about 300KB/s As soon as I disabled the torrent everything works. This just so strange. Right now I have to cap the download to about 1MB/s for my router not to crash.

[rafi]

did you try an upload limit ? say, 250K ? 500K ?

also - disabling bt.tcp_rate_control = false is helpful.

And as a last resort: disable "bandwidh management"

[supergregg]

The bandwidth manager has been turned off the whole time.

I did find a strange thing. If I cap the upload to say 100K and start a download, the speed rises to about 2.3MB/s and is very erratic. The upload limit seams to cap the overhead to and by that limiting my download speed. If I then remove the upload cap the speed shoots to about 8MB/s and then starts slowly to decline. I can see this effect clearly in the graph in uTorrent. While the slowdown happens I cannot surf the internet at all. uTorrent is still downloading but all other internet access is blocked. As soon as I Stop the download. All internet traffic is restored and all is well. So after testing an retesting it seams that I cannot download faster tan about 2MB/s, then the router starts to mess with internet browsing and after a while crashes all together requiring a restart by unplugging power.

I can now confirm that this happens to a friend of mine to with the same set up.

I will be sending a bugreport to dlink about this but It would help to know more exactly what causes it. It has to be a combination of the router and the new uTorrent. For me its obvious that the fault is in the router. But the question is what causes it? It cant just be the speed and/or number of connections.

[rafi]

Oh, I thought you had "bandwidth management" enabled (using utP). You need a ~5-10% of your download as upload overhead. So, for a 4MB download you *need* to set a ~300K UL limit.

The settings I gave are only relevant to uTP (bandwidth management" = enabled). It suppose to solve this internet usage issue . So you might as well give it a try.

[supergregg]

I have been giving it a try. But It was the first thing I disabled after my router started crashing for no apparent reason. Having this on or off makes no difference to the crash problem. The speed might be lower with BWM enabled but it is still way over what my router can take at this point.

[Switeck]

What's bt.connect_speed and net.max_halfopen set to?

[supergregg]

bt.connect_speed was set to 3 as rafi told me to set it. Earlier it was default:5.

net.max_halfopen is right now 400. Hmm.. Must have changed with the latest Beta. Last time I looked it was set to 100. I have had it set to as low as 4 and still no real improvement except low download speed. I'm using windows 7 Ultimate so what I understand there is no half-open limit there. So there is still some kind of compatibility problem with uTorrent and my dlink router.

[rafi]

Win7/x64 ? What NIC/driver ? How is your MTU set on the router ? (ping -l XXX -F <IP> , XXX - the largest size you can get out) ?

[supergregg]

Win7 x64

max MTU is 1472

The NIC is: Generic Marvell Yukon 88E8065

driver is the default that came with windows.. might have been updated over Windows update.. version is: 11.0.5.3

[rafi]

1472 is the ping result (overall MTU) ? or Windows ? result from here http://www.speedguide.net/analyzer.php ?

[supergregg]

« SpeedGuide.net TCP Analyzer Results »

Tested on: 03.08.2010 12:41

IP address: 85.227.xxx.xxx

Client OS: Windows 7

TCP options string: 020405b401010402

MSS: 1460

MTU: 1500

TCP Window: 64240 (multiple of MSS)

RWIN Scaling: 0 bits

Unscaled RWIN : 64240

Recommended RWINs: 64240, 128480, 256960, 513920, 1027840

BDP limit (200ms): 2570kbps (321KBytes/s)

BDP limit (500ms): 1028kbps (128KBytes/s)

MTU Discovery: ON

TTL: 116

Timestamps: OFF

SACKs: ON

IP ToS: 00000000 (0)

[Switeck]

uTorrent v2.x recent updates change net.max_halfopen on Win 7 (and Vista SP2) from the default of 8 to 400. Obviously this proved excessive in your case.

[rafi]

recommended RWINs: 64240, 128480, 256960, 513920, 1027840

BDP limit (200ms): 2570kbps (321KBytes/s)

if this was on XP - I would say set your RWIN to 256960 ... not sure it's required on Win7.

[supergregg]

I have already tested the HalfOpen problem and it does not help. The RWIN is probably the one coming from the router. So I doubt I can do anything about it. But the main problem still persists. Router crashing when speed increases above 3MB/s. But I see that this is going nowhere so obviously it is more than a setting in uTorrent. There must be a more fundamental difference in the way it transmits and receives packets and simply overwhelming the router.

I will be turning to Dlink with this problem because it obviously wont be solved here.

Thanks for all the help.

[Switeck]

Yes, D-Link is probably to blame based on what seems likely from your info.

[supergregg]

Thought I'll give you all some info on how this is progressing. The problem is for now solved. It was a firmware issue. I received a new beta firmware "DIR825B1_FW201EUB17Beta02.bin" dated 4, dec, 2009 from Dlink and now the router is performing as before.

Thanks for all the help!