Internal VIP with pool members on same internal network

You can use SNAT (automap or pool) to make it work. Basically you need a way so that server send the request back to the LTM. With SNAT, the server sees request coming from LTM and sends the response back to LTM. If this VS is going to have heavy traffic or if you multiple VS using SNAT then I would suggest using SNAT POOL. Basically SNAT automap, NAT's client to the exit interface IP address. You can reach the ephemeral ports limit with heavy traffic (I had seen this DNS flood). With SNAT pool, you define pool of IP's which are specifically used for NAT. You have to also consider the idle time values for SNAT.