networks//port

A port is the number that tells apart the services listening on one IP address, each service getting its own.

A port is the number that tells apart the services listening on one IP address, each service getting its own.

An IP address is a building and its ports are the apartment numbers.

Each service lives behind its own door.

Ports below 1024 are the well-known or privileged ones (HTTP on 80, HTTPS on 443, SSH on 22), and binding them often requires admin rights.

Ports from 1024 to 49151 are registered ports: 8545 for the Besu RPC, 30303 for Besu P2P, 3000 for development servers.

Besu uses two main ports: p2pPort (30303) for the horizontal traffic between nodes, and rpcPort (8545) for the vertical traffic from an application to its node. Under Docker, port mapping can expose a container's port under a different host number (-p 9999:8545), which avoids conflicts when several nodes run on one machine.