going on in the network. With CPR option enabled you can tell either
somebody is online, or not -- nothing less, nothing more.
+@item When should I use @ref{Timesync, time synchronization} option?
+Without that option, if someone captured initial handshake packet from
+the valid client, then it could repeat it and receive a handshake packet
+as an answer from server. This can be used to detect if some user's
+identity is known to server and that it is exactly GoVPN server.
+Timesync option forces adding timestamps to each handshake packet
+allowing only specified time window of packet validness. If you have got
+more or less synchronized clocks between your clients and server, then
+you can use always use this option.
+
@cindex DoS
@item Can I DoS (denial of service) the daemon?
Each transport packet is authenticated first with the very fast UMAC