Datagroup / Access class match not working.

Sets the connection to forward IP packets. This is strict forwarding and will bypass any pool configured on the virtual server.

The request will be forwarded out the appropriate interface according to the routes in the LTM routing table. No destination address or port translation is performed.

Try removing your forward command and changing up your iRule logic.

when CLIENT_ACCEPTED {
  if { ![class match [IP::client_addr] equals mynetwork] } {
      discard
 }
}
when HTTP_REQUEST {
   HTTP::redirect http://my.website.com/main/MWS-autologin.cfm?x=testing123four
}

Hope this helps.