source address & source port persistence

It looks like:

1. There should not be a problem with backends (Gateways) doing SSL offload as you're persisting on TCP level
2. The following example suggests that you first need to do "persist add uie": https://devcentral.f5.com/wiki/iRules.ProxyAuth.ashx

Thus the iRule transforms into:

when CLIENT_ACCEPTED { 
    set client_ip_port "[IP::client_addr]:[TCP::client_port]"
    persist uie $client_ip_port
}
when SERVER_CONNECTED {
    persist add uie $client_ip_port 3600
}