F5 Automap and None mapping

snat automap uses the egress vlan interface ip. by establishing a snat pool, and attaching, you can control what IP this translates to.
For the Client->F5->Server, consider these scenarios:

1. None, client source address goes to the server. Routes necessary back through BIG-IP on servers or servers gw
   
   
2. Snat Automap, client source is managed on BIG-IP, source is translated to self IP on egress interface heading toward servers. For servers needing source IP for reporting or decision processes, must insert in an application header or possibly in tcp options.
   
   
3. Snat Pool, client source is still managed on BIG-IP, but source is translated to an IP you configure and attach to the virtual server. I like this option because I can map external IP -> internal IP by application so I know what flows belong to what application on the inside of the organization/dmz as appropriate. If traffic isn't necessary to come back through the BIG-IP, can also snat to the original client's source IP.
   
   
   the most common option is "None" which do not change the source and Automap to change the Source to SB interface