erigon-network-ports - SKILL.md Agent Skill

name: erigon-network-ports user-invocable: false description: Reference for all Erigon network ports. Use this when running multiple Erigon instances to avoid port conflicts. Lists every CLI flag that binds a port, its default value, and the protocol used. allowed-tools: Bash

Erigon Port Reference

When running multiple Erigon instances on the same machine, every listening port must be unique per instance. Erigon will fail at startup if any port is already in use, reporting bind: address already in use.

All Ports That Must Be Changed

CLI Flag	Default	Protocol	Description
`--private.api.addr`	`127.0.0.1:9090`	TCP (gRPC)	Internal gRPC API for component communication (txpool, rpcdaemon, sentry, downloader)
`--http.port`	`8545`	TCP	JSON-RPC HTTP server
`--authrpc.port`	`8551`	TCP	Engine API (consensus layer auth RPC)
`--ws.port`	`8546`	TCP	WebSocket RPC server
`--torrent.port`	`42069`	TCP+UDP	BitTorrent protocol for snapshot downloads
`--port`	`30303`	TCP+UDP	DevP2P network listening port (all eth versions multiplexed)
`--caplin.discovery.port`	`4000`	UDP	Caplin consensus DISCV5 discovery
`--caplin.discovery.tcpport`	`4001`	TCP	Caplin consensus DISCV5 TCP
`--sentinel.port`	`7777`	TCP	Sentinel (consensus p2p service)
`--beacon.api.port`	`5555`	TCP	Beacon Chain REST API
`--mcp.port`	`8553`	TCP	MCP (Model Context Protocol) RPC server

Conditional Ports (only if enabled)

CLI Flag	Default	Protocol	Description
`--pprof.port`	`6060`	TCP	Go pprof profiling HTTP server (requires `--pprof`)
`--metrics.port`	`6061`	TCP	Prometheus metrics HTTP server (requires `--metrics`)

Example: Two Instances

Instance 1 (using defaults):

./build/bin/erigon --datadir /path/to/datadir1

Instance 2 (all ports offset by +100):

./build/bin/erigon --datadir /path/to/datadir2 \
  --private.api.addr=127.0.0.1:9190 \
  --http.port=8645 \
  --authrpc.port=8651 \
  --ws.port=8646 \
  --torrent.port=42169 \
  --port=30403 \
  --caplin.discovery.port=4100 \
  --caplin.discovery.tcpport=4101 \
  --sentinel.port=7877 \
  --beacon.api.port=5655 \
  --mcp.port=8653

Notes

--private.api.addr takes a full host:port value, not just a port number.
The torrent port binds on both TCP and UDP; it is typically the first port conflict encountered at startup.
If --pprof or --metrics are enabled on both instances, their ports must also differ.