FIP for the back end interface

Hi

Okay have 2 F5's in cluster

then both have interface into the front end VLAN. and I assign a floating ip to that side, so that I can attach a VS to it.

Now do I need to do the same for the back end and how do I get the F5 to use the FIP as the SNAT address

if I mirror between the F5, would this mean that if the active node dies the session will continue on the other node (client to F5 & F5 to backend)