Monitoring proxy server pool/nodes using an external website

This is what I did.

Create an HTTP monitor. My proxy pool is a port 0 pool(to proxy other things like ftp) so I assigned the monitor to use port 8080(the explicit proxy port)

The Send String should be a standard proxy GET request. Note a proxy GET request relies on the full URL to be in the GET request, not just the path. Example

GET http://www.domain.com/robots.txt HTTP/1.1\r\nHost: www.domain.com\r\nConnection: close\r\n\r\n

The receive string should be what you are looking for. Example:

Disallow: /search

Finally, on the proxy, I set an authentication policy so that the LTMs did not have to authenticate when going to the external sites I used to monitor. That way I did not have to do authentication in the monitor.