blockchain//bootnode

A bootnode is the discovery entry point of a network: new nodes contact bootnodes to learn about the other peers. It is not a special node type, and any node can be a bootnode if others list its enode, the URL that carries both its identity and its network location, in `--bootnodes`.

A bootnode is the discovery entry point of a network: new nodes contact bootnodes to learn about the other peers. It is not a special node type, and any node can be a bootnode if others list its enode, the URL that carries both its identity and its network location, in --bootnodes.

After the initial discovery, nodes find each other through gossip, and the bootnode's job is done. If the only bootnode dies, the existing nodes keep working because they already know their peers; only newcomers are affected.

Several bootnodes give resilience: if one goes down, newcomers can use the others.

The best topology has the bootnodes point at each other (A lists B and B lists A), with every node listing both.