You upgrade Microsoft Internet Security and Acceleration (ISA) Server 2000 to ISA Server 2004. Additionally, ISA Server 2004 is part of Microsoft Windows Small Business Server 2003 (Windows SBS) Service Pack 1. In this scenario, you may experience the following symptoms:
The client computer cannot correctly connect to certain Web sites, and the page is incomplete.
An application cannot correctly connect to the Windows SBS server to obtain its resources.
One or both of the following events may be logged in the Application log on the ISA Server computer:
Event Source: Microsoft Firewall Event Category: Packet filter Event ID: 15113 Type: Warning Description: ISA Server disconnected the following client: IP address because its connection limit was exceeded.
Event Source: Microsoft Firewall Event Category: Packet filter Event ID: 15112 Description: The client x.x.x.x exceeded its connection limit. The new connection was rejected.
This problem occurs because the connection limit of 40 from ISA Server 2000 is maintained in the upgrade to ISA Server 2004. A connection limit of 160 is the default in clean installations of ISA Server 2004.
Note ISA Server 2000 in included in Windows SBS Premium Edition. ISA Server 2004 is included in Windows SBS Premium Edition with Service Pack 1.
To resolve this problem, increase the connection limits to 160. To increase connection limits, follow these steps:
In the console tree of ISA Server Management, click General, and then do the following, as appropriate for your situation:
ISA Server 2004 Enterprise Edition
Expand Microsoft Internet Security and Acceleration Server 2004, expand Arrays, expand Array_Name, expand Configuration, and then click General.
ISA Server 2004 Standard Edition
Expand Microsoft Internet Security and Acceleration Server 2004, expand Server_Name, expand Configuration, and then click General.
In the results pane, click Define Connection Limits.
On the Connection Limit tab, select Limit the number of connections, and then do the following:
In Connections created per second, per rule (non-TCP), type the number of connections that are allowed per second, per rule.
In Connection limit per client (TCP and non-TCP), type the number of connections that are allowed per client.
Note The default number of connections on a clean install is 160.
To override the default connection limit for specific IP addresses, in Custom connection limit, type the maximum number of connections that are allowed for specific users.
Click Add to add computer sets to which these limits apply.
Click Apply to save the settings.
Note The connection limits value may have to be larger than 160.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
838706 Cannot connect to a service from a particular client computer in ISA Server 2004