Windows Server2003 IIS6.0 logs a large number of connections_refused error resolution

Recently published sites are run on the Windows Server2003 IIS6.0 site, and sometimes all sites are inaccessible. On the internet to find a bit of information, finally resolved: The information is as follows:

Symptoms:

You experience the following symptoms when you run Microsoft Windows Server 2003, Microsoft Exchange Server 2003, and Microsoft Internet Information Services (IIS) 6 .0 on the server:
When a user tries to use Microsoft Office Outlook Web Access or to view a Web page that is hosted on a server, the user receives the following error message:
This page is not displayed.
The page you are looking for is currently unavailable. The site may be experiencing technical difficulties, or you may need to adjust your browser settings.
The server could not be found or a DNS error occurred.
When you view the Httperr.log file, you will see several matching entries as follows:
Ref. _connections_refused "_msthash=" 1000506 "> 编号 _connections_refused
Note
You must have HTTP Api error logging enabled.
The Httperrlog_number.log file is located in the following folder:
\system32\logfiles\httperr

Reason:

This problem occurs if the nonpaged pool memory that is less than 20 megabytes (MB) is available on the server. when nonpaged pool memory is less than 20 megabytes (MB), the HTTP. SYS kernel-mode driver stops accepting new connections.

This issue may occur in cases where the /3GB switch is enabled in the boot. ini file on the server.

Workaround:

To resolve this issue, add the Enableaggressivememoryusage registry key to the following registry subkey:
Hkey_local_machine\system\currentcontrolset\services\http\parameters
Then, set the Enableaggressivememoryusage registry key to 1.
Please perform the following steps:
Click Start, Run, type regedit in the Open box, and then click OK
Click the following registry subkey:
Hkey_local_machine\system\currentcontrolset\services\http\parameters
On the Edit menu, point to New, and then click DWORD Value
Type Enableaggressivememoryusage, and then press ENTER.
On the Edit menu, click Modify
In the Value data box, type 1, and then click OK
On the File menu, single-Exit to quit Registry Editor.
Restart the HTTP service. Please perform the following steps:
Click Start, click Run, type cmd in the Open box, and then click OK
At the command prompt, type net stop http/y, and then press ENTER.
At the command prompt, type Iisreset/restart, and then press ENTER.

From Microsoft Official: Http://support.microsoft.com/kb/934878/zh-cn#top

Windows Server2003 IIS6.0 logs a large number of connections_refused error resolution