I tried to catch any packets sent to that ip during the silkroad client is opened but there wasnt any packet. But i just started catching them after i was already logged in.
The connection was all the time alive.
That gameguard is a possibilty, i also saw that then connection is opening after choosing the character and entering the game not on the log on screen
@Synx7 my client including the Server 5 and was downloaded from their page