client.exe stops responding, TCP connections

While using Bitlord (a BitTorrent client). It's not very common and doesn't crash every time, but it's common enough to irritate me. I've ensued the problem a while now, and it seems to be a problem with too many TCP connect attempts.

MS Event viewer shows this warning in the system area when client.exe stops responding:

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TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts.
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Ideas to get rid of the problem?

WinXP allows only 10 connections to be opened very quickly at the same time. Try this patch. It worked for me.

http://www.lvllord.de/?lang=en&url=downloa...e4330d6c19ca877

Also, most routers only support up to 100 connections at a time. After I found out that my D-Link only supports 70 connections, I limited BitTorrent to 70 max connections (instead of 200), and all my troubles were fixed. The problems I had were webpages would timeout, and my mail counter in my config would stop working, etc.

*moved to misc support, because it's not a problem with Samurize*

Thanks a lot uziq! Yeah wasn't sure could it be something odd or common related to Sammy.

I'll run the patch. Will find out how many TCP connections my A-Link RR44c supports, don't think its very many, it's a cheap one.

Here's an article on some routers that are supposed to be good for P2P:

http://www.tomsnetworking.com/2006/04/19/w...router_for_p2p/

HMM, just got mail from A-Link, they claim my router supports 1024 simultaneous TCP connections, I pretty much doubt that, but if it is so many, sounds like that WinXP problem. Haven't actually tried the patch yet, testing still.

The information in this thread is incomplete, not entirely accurate, and may mislead users to download a patch that is most probably not required.

Changes to Functionality in Microsoft Windows XP Service Pack 2 - TCP/IP

Quote from Microsoft:

"Limited number of simultaneous incomplete outbound TCP connection attempts— The TCP/IP stack now limits the number of simultaneous incomplete outbound TCP connection attempts. After the limit has been reached, subsequent connection attempts are put in a queue to be resolved at a fixed rate. Under normal operation, when applications are connecting to available hosts at valid IP addresses, no connection rate-limiting occurs."

This limit is a rate limiter, not a connection limiter. You can have tons of half-open connections, just not have them initialised all at the exact same time.

Thanks for the correction risk3.

Anyway at least that patch resolved the issue I had at that time.

We already knew that. And the patch fixes it.

I appreciate that, uziq. I just wanted to make clear that Windows XP will allow as many connections (and total attempts) as you want (depending, of course, on your PC's capacity) as long as the connections are made at 10 a second (more than 10 attempts a second will trigger the above mentioned entry in the Event Viewer).
For most people on a proper high speed connection the patch is unnecessary.

Patch worked fine with my high speed cable connection

Same here with 8M/1M DSL connection.

I don't think the DSL speed has anything do with this.

I think you'll likely benefit from the patch more with a fast connection than a slow one, because you'll be able to send more data, quicker (potentially opening hundreds of connections at once, as P2P programs like to do).

@KMDonlon & Spewed

I am glad the patch works for you but the discussion is about whether one need to patch tcpip.sys or not. The point is that Torrents work correctly on Windows XP SP2 without the patch. Windows XP does not impose a limit on the number of established connections. Earlier posts did not make that clear. It's a speed issue but only at the beginning of downloading (again, not downloading speed but how fast you make the connections target). If one would like to increase the limit on connection attempts per second, LvlLord's EventID 4226 Patcher can do that, but I still maintain that a patch is not necessary for everyone!

Yes that's pretty obvious isn't it? No one hasn't claimed here everyone should run the patch but those who have similar issues.