Bootstrap

Chapter 26: Node Bootstrap & Static Peers

Overview

Bootstrap nodes help new nodes join the network, while static peers provide guaranteed connections. This chapter covers bootnodes, seeds, persistent peers, and how to pin your node to a trusted peer set — plus how that differs across ecosystems.

26.1 Bootnodes

What are Bootnodes?

Bootnodes are well-known, long-running nodes that help new nodes discover peers. They are the “phone book” of a P2P network: a new node knows a few bootnodes’ addresses out-of-band (hardcoded or configured), asks them for peers, and then leaves.

NEW NODE                     BOOTNODE                    PEER NETWORK
   │                            │                              │
   │  1. "Who do you know?"     │                              │
   ├───────────────────────────▶│                              │
   │                            │  2. share peer table         │
   │◀───────────────────────────┤                              │
   │  3. connect directly       │                              │
   ├──────────────────────────────────────────────────────────▶│
   │  4. discovery continues via  5. bootnode drops out        │
   │     DiscV5 / gossip            (connection no longer needed)

Ethereum Bootnodes

# geth: pass one or more bootnode ENRs
geth --bootnodes "enr:-KG4QOtcL...@bootnode.mainnet.ethdisco.net:30303"

# Multiple bootnodes
geth --bootnodes \
  "enr:...@node1:30303,enr:...@node2:30303,enr:...@node3:30303"

Bootnodes vs Seeds (Different Ecosystems)

Term	Ecosystem	Meaning
Bootnode	Ethereum	Known ENRs for initial DiscV5 bootstrap
Seed	Cosmos/CometBFT, Bitcoin	Known node addresses in `config.toml` / `-seednode` that provide peer lists
Entrypoint	Solana	Hardcoded gossip addresses (`--entrypoint entrypoint.mainnet-beta.solana.com:8001`)
Well-known peers	Polkadot	Nodes shipped in `chain_spec` for bootstrapping

26.2 Static Peers (Ethereum)

Why Static Peers?

Guaranteed connectivity (independent of discovery)
Useful for private networks and sentry→validator links
Backup peers when discovery is unreliable

Configure Static Peers

Geth loads static peers from static-nodes.json in the data directory (there is no config.toml for this — and --staticnodes is not a geth flag):

# <datadir>/geth/static-nodes.json
# (plain JSON array of enode:// or enr:// URLs)
echo '["enode://abc123...@peer1:30303","enode://def456...@peer2:30303"]' \
  > /data/ethereum/geth/static-nodes.json

# For older geth versions the file is <datadir>/static-nodes.json

Add Dynamically

geth attach http://localhost:8545
> admin.addPeer("enode://abc123...@peer1:30303")
# → true
> admin.peers

26.3 Persistent Peers in Other Ecosystems

Cosmos / CometBFT

config.toml — persistent_peers are kept regardless of discovery; the sentry architecture depends on them:

[p2p]
seeds = "id@seed1:26656,id@seed2:26656"
persistent_peers = "id@sentry1:26656,id@sentry2:26656"
pex = true          # false on a validator behind sentries

Bitcoin

bitcoin.conf — -addnode forces a connection even if the peer isn’t useful; -connect restricts to ONLY those peers:

# bitcoin.conf
# Add a trusted peer (will try to keep both directions)
addnode=1.2.3.4:8333
# Restrict all connections to these (private/regtest style):
# connect=1.2.3.4:8333

Solana

Solana nodes “trust” --known-validator addresses for snapshot + gossip bootstrap instead of persistent peers:

solana-validator --entrypoint entrypoint.mainnet-beta.solana.com:8001 \
  --known-validator <KNOWN_VALIDATOR_PUBKEY>

26.4 Best Practices

Always configure multiple bootnodes/seeds — a single hardcoded address is a single point of failure (and a trust risk if compromised).
Verify the address format before pasting: enode://<pubkey>@ip:port / enr: for Ethereum, id@host:26656 for Cosmos.
Private networks & sentries: use static/persistent peers + disable discovery (--nodiscover, pex = false) so only your controlled peers join.
After changing peer config, verify with admin.peers (geth) or curl localhost:26657/net_info (Cosmos) before declaring the node healthy.

Summary

Bootnodes for initial peer discovery
Static peers for guaranteed connections
Use multiple for redundancy
Ethereum: static-nodes.json or admin.addPeer (no --staticnodes flag)
Cosmos: seeds + persistent_peers in config.toml
Bitcoin: addnode / connect; Solana: --entrypoint + --known-validator

Last Updated: 2026-09-28