A method allows message transmission in a peer-to-peer network using chord topology, in which some of the nodes have access protection which allows reception of messages only from those network addresses to which a message has previously been sent. A network such as this is dependent on each node maintaining a list with further nodes, referred to in general as a finger list. In order to allow communication despite access protection, each node sends a request at fixed time intervals to the nodes in its list, to send it a message. This makes it possible for each node to send messages to the nodes in its list. A search request for a file is passed on via intermediate nodes in the network such that the searching node is provided with access to a destination node which can offer the file, and the access protection of the destination node is cancelled.