1.6 KiB
ETH 2.0 Networking Spec - Node Identification
Abstract
This specification describes how Ethereum 2.0 nodes identify and address each other on the network.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL", NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.
Specification
Clients use Ethereum Node Records (as described in EIP-778) to discover one another. Each ENR includes, among other things, the following keys:
- The node's IP.
- The node's TCP port.
- The node's public key.
For clients to be addressable, their ENR responses MUST contain all of the above keys. Client MUST verify the signature of any received ENRs, and disconnect from peers whose ENR signatures are invalid. Each node's public key MUST be unique.
The keys above are enough to construct a multiaddr for use with the rest of the libp2p stack.
It is RECOMMENDED that clients set their TCP port to the default of 9000.
Peer ID Generation
The libp2p networking stack identifies peers via a "peer ID." Simply put, a node's Peer ID is the SHA2-256 multihash of the node's public key struct (serialized in protobuf, refer to the Peer ID spec). go-libp2p-crypto contains the canonical implementation of how to hash secp256k1 keys for use as a peer ID.