How do bitcoin nodes initially find peers? [duplicate]

Question

In all materials related to bitcoin, the people talk about the p2p bitcoin network.

OK, but there should be a central server that connects the peers to each one. Like the torrent sites. The torrents are p2p but before you can start talking with the other nodes from the p2p network you should know who they are(ip addresses). That's why you are getting the torrent file-you should know who else is interested in this torrent and start talking with him.

But in internet I can't find information about the central bitcoin server -that makes the p2p clients to see each other? Where I am wrong? Thanks Tonko

Answer 1

Although the torrent protocol requires a central server, you don't necessarily need a central server for a p2p network. The client only needs the IP address of at least one active participant. Connecting to this will give you other IP addresses to connect to.

So the only problem for a p2p network without a central server is: where to find the first IP address to connect to. Bitcoin solves this using a so called IRC bootstrap after the first installation. Basically it tries to find such ip-addresses on designated IRC channels.

This is only necessary on first run; subsequence runs it will just try ip addresses that have worked before.

More info on the IRC bootstrap: http://bitcoinmedia.com/the-irc-bootstrap-method-is-flawed/

EDIT: On further inspection, it seems that IRC bootstrapping is no longer used. See the link for details.

EDIT: See also this question regarding the initial connection (bootstrapping)