On one side you can ping the server IP to detect wether it is responsive. You can set a short timeout for InetPing so that your app is not handicapped.
On the other hand, you must manage TCP_DISCONNECT event in the client callback and take the appropriate countermeasures if it fires.
Once made this, the server usually have no other troubles, but I suggest you to record all abnormal event you get together with any detail available, including runtime errors and function on error.
