What Hamish says is exactly right on...
You will need to create a self IP and floating IP on the LTM for your HTTP/inside vlan. This means you'll need 3 IP's per inside vlan - one for the active unit, one for the standby unit and one floating IP across both units (provided you have a HA set up).
The real machines (nodes) in the http.linweb.pool will then have their default gateway changed to that of the floating IP. This is very important so that the return traffic will go back via the LTM so in effect it makes the virtual server act very much like a "router".
HTH
Andy