Peer-to-Peer (P2P) Networks
Peer-to-peer networks are distributed systems where participants (peers) share resources directly with each other without relying on centralized servers.
Peer-to-peer (P2P) networks are a foundational technology for decentralized systems, where each participant (peer) acts as both client and server. Unlike client-server architectures, there's no central point of control or failure, making P2P networks resilient and censorship-resistant.
Key components include: peer discovery (finding other nodes—DHT, bootstrap nodes, mDNS), data routing (getting messages to correct peers), content addressing (identifying data by hash rather than location), and gossip protocols (efficient information propagation).
In blockchain, P2P networks distribute transactions and blocks across all nodes, enabling decentralization. Popular P2P implementations include libp2p (used by Ethereum, IPFS, Filecoin), devp2p (Ethereum's original), and Bitcoin's custom P2P protocol. Each handles node discovery, connection management, and message routing.
Challenges include NAT traversal (reaching nodes behind firewalls), eclipse attacks (isolating nodes), Sybil attacks (fake identities), and network partitions. Solutions include hole-punching, peer reputation systems, and redundant connections.
graph LR
Center["Peer-to-Peer (P2P) Networks"]:::main
Pre_networking["networking"]:::pre --> Center
click Pre_networking "/terms/networking"
Pre_distributed_systems["distributed-systems"]:::pre --> Center
click Pre_distributed_systems "/terms/distributed-systems"
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