Packet Filter Driver Blocks All Non-proxy Requests

The information in this article applies to:

• Microsoft Proxy Server version 2.0

SYMPTOMS

The packet filter driver in Proxy Server version 2.0 blocks all non-proxy requests to and from the Proxy Server.

CAUSE

This only occurs when packet filtering is selected (enabled). The packet filter driver will not block applications that use any of the proxy services. Instead, the dynamic packet filter feature will automatically open the requested ports for these applications.

RESOLUTION

If you run applications that access the Internet on the same computer that is running Proxy Server, you need to configure static filters.

To add a custom or pre-defined static filter:

1. Under Shared Services, click Security and select Add.

2. Select one of the pre-defined packet filters or use a sample from the list of packet filters below to create a custom packet filter.

   The Local Host and Remote Host parameters can be adjusted to allow connections to or from selected IP addresses.

Common Packet Filters

FTP Server IN (Filter 1 of 2) Protocol = TCP Direction = IN Local Port = 21 Remote Port = Any

FTP Server OUT (Filter 2 of 2) Protocol = TCP Direction = OUT Local Port = 20 Remote Port = Any

HTTP Server (Port 8080) (Note, there is a pre-defined filter for port 80) Protocol = TCP Direction = IN Local Port = 8080 Remote Port = Any

MORE INFORMATION

For additional information on packet filters, please see the "Setting Security Parameters" chapter in the Microsoft Proxy Server version 2.0 documentation. This article will be updated periodically with new packet filter examples.