# Bootnode ## Options - ```listen-addr```: listening address of bootnode (:) (default: 0.0.0.0:30303) - ```v5```: Enable UDP v5 (default: false) - ```log-level```: Log level (trace|debug|info|warn|error|crit) (default: info) - ```nat```: port mapping mechanism (any|none|upnp|pmp|extip:) (default: none) - ```node-key```: file or hex node key - ```save-key```: path to save the ecdsa private key - ```dry-run```: validates parameters and prints bootnode configurations, but does not start bootnode (default: false)