Important This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
- The client makes an internal Local Address Table (LAT)-based HTTP 1.1 request to the server that includes a "Proxy-Connection: Keep-Alive" request header.
- The client makes an external reverse-proxy (Web-published)-based HTTP 1.1 request that includes a "Connection: Keep-Alive" request header.
HTTP 1.1 adds the "Proxy-Connection:Keep-Alive" header and the "Connection:Keep-Alive" header to reduce the number of TCP connections that are made during a single Web session between the client and the server. ISA Server maintains a connection to the remote server for client requests so that each request to the remote server travels over a single connection. This makes the overall session far more efficient, and the session is then used to service all ISA clients that request connections to the same server, unless server authentication is used. In cases where server authentication is used, a new TCP connection is created for each authenticated session.
To modify the default behavior of ISA Server, set the ConnectCacheSizeregistry value in the following registry key to 0 (zero):
Important If ISA Server is also used for Web publishing, you must obtain the fix that is described in the following Microsoft Knowledge Base article before you set the ConnectCacheSizevalue to 0:
To set the ConnectCacheSize registry value to 0, follow these steps:
- Click Start, and then click Run.
- In the Open box, type regedit, and then click OK.
- Locate and then select the following registry subkey:HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W3Proxy\Parameters
- In the right pane, click ConnectCacheSize.
- On the Edit menu, click Modify.
- In the Value data box, type 0, and then click OK.
- Quit Registry Editor.
Note The ISA Server Web Proxy service must be restarted for this change to take effect.
For more information about the Web Proxy service, visit the following Microsoft Web site: