Self-IP & SNAT

When using SNAT I always recommend using a SNAT Pool that uses the virtual server IP so you have a way of tracking what SNAT connections go where and you don't run the risk of exhausting the self-IP ephemeral ports that are used for things such as health monitors because with automap uses the self-IP closer to the destination pool member. You can absolutely use a SNAT IP that exists within the same subnet as the pool members as long as the F5 has a self-IP within that subnet.