HTTP monitor shows nodes unknown(enabled)

Two things. To answer your first query, the default http monitor uses http version 0.9 so it might be that the webserver is rejecting this old http version. If you construct a http 1.1 monitor it sounds u have more success.

On your second point, if the pool us Up and the VS too then what is the webserver's default gateway? Does return traffic to the client go back via hr bigip ie it's inline? If you then try using SNAT Automap in your VS config. This changes the source address to be the bigip.

Hope this helps,

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