-----Original Message-----
From: "John T (lists)" <[EMAIL PROTECTED]>
Sent 3/29/2007 12:05:46 PM
To: [email protected]
Subject: RE: [IMail Forum] TCP sockets & Windows -> maybe associated with 2006.2 issues
I concur, made those changes late last night and still seeing
the problems this morning.
The only thing I have found that helps is to recycle the
application pool on a timed basis of say every hour.
John T
From:
[EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Stephan
Sent: Thursday, March 29, 2007 7:43 AM
To: [email protected]
Subject: Re: [IMail Forum] TCP sockets & Windows -> maybe
associated with 2006.2 issues
I've made theses modifications a long time ago, which did
fix some other problems with 2006.1, but I am still seeing problems with 2006.2
webmail with these tcp settings enabled.
-----Original Message-----
From: "Matt" <[EMAIL PROTECTED]>
Sent 3/28/2007 2:25:35 PM
To: [email protected]
Subject: [IMail Forum] TCP sockets & Windows -> maybe associated with
2006.2 issues
I have run into TCP socket limitations with two different E-mail servers that
run on Windows. Both were the result of using too many TCP sockets.
Windows by default will only allow around 1,800 sockets to be used, and when
you start getting to that point, unexpected things can happen. Sockets
are used for SMTP connections, POP3 connections, IMAP connections, DNS lookups,
and all sorts of .NET stuff too. Things like greylisting will keep
sockets open for long periods of time, and systems that do spam blocking with
DNS lookups to blacklists tend to push out more than is typical. A good
program designed to handle such load will pool the sockets in order to avoid
hitting these limits. Both products that I had issues with introduced
pooling in order to resolve these issues.
As a work around, or for tuning a Windows server that does such things, I
recommend changing or adding the following registry parameters:
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\MaxHashTableSize
= 65536 (DWORD)
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpTimedWaitDelay = 30
(DWORD)
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\MaxUserPort = 65534
(DWORD)
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpNumConnections,
16777214 (DWORD)
You can google each key name
for a description of what they do. This can definitely help if there are
issues with the TCP sockets, but it's not a permanant solution. The
permanent solution is to have the application pool if it isn't already.
If this helps, it would definitely be good to share that with this list and/or
Ipswitch in the event that they are still looking for the problem.
Matt
