Infamous CLOSE_WAIT

[Catscratch]

No matter what I do, i can't seem to prevent uTorrent from leaving close_wait connections after closing it. And it seems be listening forever according to Sunbelt Personal Firewall. After 2 hours I terminated uTorrent, it's still listed in my firewall listening to 100+ connections and netstat shows lotsa close_wait connections.

That bored me and I blocked utorrent access to internet this reduced "connected in" numbers but when I give access back, it starts connecting back to ips.

Now how can a program I terminated still make new connections ? Why does it leave close_wait connections behind as it's clearly uTorrent's fault because it received close msg from the client yet refuse to actually close the connection ?

[DreadWingKnight]

The problem isn't uTorrent.

Once uTorrent closes a connection, control of that connection is passed off to the operating system. If your timeouts are being interfered with, then the close_wait connections will continue to build up.

[Catscratch]

While this may seem true, the timeout you mentioned is for time_wait not close_wait.

close_wait is application dependent, Windows XP never interferes with close_wait connections and there are no timeouts for it.

Now even if it was OS's problem to close those connections, why do OS tries to connect back ? I know firewall lists those connections under Utorrent because of the port the program uses but why uTorrent has to leave connections behind like that ?

SOLVED - One more thing, why does uTorrent keep visiting through trackers of STOPPED/INACTIVE torrents in my list ? I guess that was scrape feature right ? Disabled

One more thing, why does my firewall says 300 total(inbound/outbound) connections for uTorrent where I only set 80 for global connection limit ? This totally puts lotsa stress on the firewall.

[jewelisheaven]

uT will only connect to the number you specify. All others are dropped ... You will see this if you enable Verbose Logging in the Logger tab. You'll know when to turn it on by Alt-H-S stats saying "connections XXX" where XXX is the max global connections you set in Preferences. bt.scrape_stopped is FALSE by default.

[Switeck]

Incoming connections meant for uTorrent are intercepted by your firewall and either let through to uTorrent or not.

Half open connections are also lingering after failing (probably due to your firewall) which also may be "stuck in memory" for a lot longer than they should be.

Your ISP may be silently killing connections, leaving your end to time out with a CLOSE_WAIT state.

Are these "stuck" ips on your incoming listening port for uTorrent or on seemingly random outgoing ports?

[Firon]

It's your firewall holding connections forever.