Perstistance on Cookie and a secondary Cookie

This is an example of irule for universal profile persistance:

ltm rule persistence_rule {
    when HTTP_REQUEST {
if { [HTTP::header exists "SessionID"] } {
    persist uie [HTTP::header value "SessionID"]
        }
    }
when HTTP_RESPONSE {
if { [HTTP::header exists "SessionID"] } {
    persist add uie [HTTP::header value "SessionID"]
        }
    }
}

My recommendation is give a try to the standard cookie persistence in F5, are far more efficient and probable you can achieve the same functionality.