Introduction
Blockchain networks consist of interconnected nodes that maintain the decentralized ledger. Understanding node types and network structures is essential for:
- Developers building blockchain solutions
- Network participants choosing their involvement level
- Enterprises evaluating blockchain architectures
This guide covers all major node types and how they form different network topologies.
1. Blockchain Node Types
Full Nodes
- Store complete blockchain history
- Validate all transactions and blocks
- Enforce network consensus rules
- Examples: Bitcoin Core, Geth (Ethereum)
Key Responsibilities:
- Verify every transaction against protocol rules
- Relay valid transactions to other nodes
- Maintain complete copy of the ledger
Light Nodes (SPV Clients)
- Store only block headers, not full history
- Rely on full nodes for transaction verification
- Ideal for mobile wallets and resource-constrained devices
Tradeoffs:
- Faster synchronization
- Lower storage requirements
- Reduced security (trust required)
Mining/Staking Nodes
- Participate in block creation
- Miners (PoW) or Validators (PoS)
- Require significant resources (ASICs for Bitcoin mining)
Key Functions:
- Bundle transactions into blocks
- Solve cryptographic puzzles (PoW)
- Vote on chain validity (PoS)
Archive Nodes
- Store full history plus intermediate states
- Required for historical data queries
- Used by blockchain explorers and analytics tools
Authority Nodes
- Found in permissioned blockchains
- Pre-approved by network governance
- Common in enterprise solutions (Hyperledger)
2. Network Topologies in Blockchain
Peer-to-Peer (P2P) Mesh Networks
Used by: Bitcoin, Ethereum, most public blockchains
Characteristics:
- Nodes connect to multiple peers
- No central coordination point
- Resilient to single points of failure
Advantages:
- High censorship resistance
- Organic network growth
- Equal participation
Hub-and-Spoke Model
Used by: Some enterprise blockchains
Characteristics:
- Central “hub” nodes with many connections
- Edge nodes connect through hubs
- Hybrid decentralization approach
Use Cases:
- Consortium blockchains
- Supply chain networks
- Financial settlement systems
Hierarchical Networks
Used by: Some DPoS and BFT networks
Characteristics:
- Tiered node structure
- Validator nodes at top level
- Regular nodes below
Examples:
- EOSIO block producers
- Binance Smart Chain validator set
Cluster-Based Topologies
Used by: Sharded blockchains
Characteristics:
- Nodes organized into shard clusters
- Cross-shard communication protocols
- Enables horizontal scaling
Implementations:
- Ethereum 2.0 shard chains
- Near Protocol’s sharding
3. Node Communication Protocols
Gossip Protocol
- New transactions broadcast to random peers
- Exponential spread through network
- Used by Bitcoin and Ethereum
Flooding Algorithm
- Nodes rebroadcast all received messages
- Simple but bandwidth-intensive
- Early blockchain implementations
RPC (Remote Procedure Calls)
- Client-server communication
- Used by light nodes querying full nodes
- JSON-RPC in Ethereum
LibP2P
- Modular network stack
- Used by IPFS and Ethereum 2.0
- Supports multiple transport protocols
4. Node Distribution Analysis
Bitcoin Node Distribution:
- ~50,000 reachable nodes
- Geographically dispersed
- Concentration in data centers
Ethereum Node Distribution:
- ~5,000 full nodes
- Many running in cloud services
- Growing number of archive nodes
5. Running Different Node Types
Full Node Requirements
| Blockchain | Storage | Memory | Sync Time |
|---|---|---|---|
| Bitcoin | 500GB+ | 4GB+ | 2-7 days |
| Ethereum | 1TB+ | 8GB+ | 1-3 days |
| Litecoin | 100GB+ | 2GB+ | 1-2 days |
Light Node Setup
- Install wallet software
- Configure to light/client mode
- Connect to trusted full nodes
Mining Node Setup
- Acquire specialized hardware (PoW)
- Install node software
- Join mining pool (optional)
- Configure wallet for rewards
6. Network Topology Impact on Performance
Throughput Considerations
- P2P networks have natural bottlenecks
- Hub models enable higher TPS
- Sharding improves scalability
Latency Factors
- Geographic node distribution
- Network propagation delays
- Block validation times
Security Implications
- More nodes = greater decentralization
- Concentrated nodes = vulnerability
- Sybil attack resistance varies
Conclusion
Blockchain networks achieve decentralization through:
- Diverse node types serving different functions
- Robust topologies balancing performance and security
- Efficient protocols for node communication
Key takeaways:
- Full nodes provide maximum security
- Light nodes enable broader participation
- Network design affects scalability and resilience
Understanding these architectures helps when:
- Choosing how to participate in a network
- Designing blockchain solutions
- Evaluating network health and security