Follow the configuration instructions for the basic network deployment scenario that you want to
use (Explicit Deployment, Transparent Deployment, or Bridged Deployment), but with the following
differences:
■
Ensure that your existing cache server is between your Web Appliance and your firewall.
■
Ensure that your cache server is configured to be transparent to the Web Appliance.
Related tasks
Downstream ISA/TMG Server Deployment
on page 27
Upstream ISA/TMG Server Deployment
on page 36
2.3.6 Upstream ISA/TMG Server Deployment
This option is similar to the Downstream ISA/TMG Server Deployment. It can be used with any
of the basic deployment options. It allows the Web Appliance to work with an ISA/TMG server,
although in this case, one that is upstream in the network from the Web Appliance (see diagram
below).
■
Allows the Web Appliance to work with an ISA/TMG server.
■
Allows you to use multiple Web Appliances in a simple load-balancing deployment.
■
Does not support individual user opt-out.
Operation
The operation varies according to the basic deployment scenario that you choose. As an example,
this option is shown in the diagram above and described in the points below as a Bridged
Deployment.
■
Users’
HTTP and HTTPS requests are passed through the Web Appliance
.
■
The Web Appliance
assesses URLs.
■
The Web Appliance
blocks disallowed requests, checks if allowed URL requests are currently
cached, and passes URL requests that are not cached through to the ISA/TMG server .
36 | Getting Started | Sophos Web Appliance