Unacknowledged fin/ack - should I use loose close?

sounds you use it where it was meant for. the session will stay around for longer, but will adhere to the configured idle time i believe.

there have been some recent SOLs about loose close issue, this one for example, but sure to check if your version is affected: http://support.f5.com/kb/en-us/solutions/public/15000/200/sol15231.html