Network discovery

The network discovery in Bitcoin is required by any node when it is first started; a node has to discover other nodes in the network to participate in the blockchain. At the start of a node, it has to connect with at least one existing node in the network.

For this, the nodes establish a connection over the TCP protocol, over port 8333 or any other port if there is one. Next a handshake is performed by transmitting a certain message. That message is called the version message, which contain basic identification information.