About upstream proxies

After configuring upstream proxy settings, you can use a single upstream proxy for all web requests.

Multiple upstream proxies

There are three potential destinations for a web request forwarded to an upstream proxy. These are as follows, in order of precedence:

  1. A pool of one or more proxies allowed by the upstream proxy policies, to service the request.
  2. The default proxy, if configured.
  3. Direct forwarding of requests to their origin servers, if allowed. An origin server is defined as the target destination of web request, in other words, the server from which a requested resource originates.

Upstream proxy policies are additive. The Smoothwall Filter checks requests against all the policies, in order. Any proxy allowed to service a request is added to the proxy pool. If the final pool for a request contains two or more proxies, load-balancing and fail-over rules decide the one that sent the request.

Note: The rules only apply to requests serviced by the Smoothwall Filter. If a device behind the Filter can obtain direct, unfiltered web access, the client’s requests are treated no differently from other Internet traffic.