How to change only IP packet's destination address?

"the source address is the IP address of F5's service interface"

 

 

This means that you have SNAT automap configured on the virtual.

 

 

" and the destination address is that of F5's virtual IP"

 

 

This means that you have address translation DISABLED within virtual server properties.

 

 

"or, the source address is the client's IP address and the destination address is that of F5's virtual IP"

 

 

This means that SNAT is set to NONE and address translation is DISABLED.

 

 

Set the virtual to Standard, SNAT to NONE, and Address translation to ENABLED. This will give you packets at the backend server having Source address of the CLIENT and Destination address of backend server.

 

 

Send configuration of virtual if you can: fom CLI, logged in as root:

 

tmsh list ltm virtual all-properties

 

tmsh list ltm pool all-properties

 

 

if you login as admin, it dumps you into tmsh so use this:

 

list ltm virtual all-properties

 

list ltm pool all-properties

 

 

HTH