fallback persistance

There doesn't seem to be a whole lot of difference between cookie and source IP persistence. If cookie-persistence is the primary and source-IP the fallback profile, most clients won't have the cookie yet when they first connect so the fallback profile will be used.

The cookie seems to be limited to the session anyway, so functionally there doesn't seem to be a big difference between the two options. I'm not sure if the cookie persistence would last longer than the IP-persistence, although it would be doubtful that the server/node would keep session information longer than the IP-persistence tables are retained.