geth --syncmode

 a consensus client is required for Geth to sync 

• geth --syncmode full
• geth --syncmode light
• geth --syncmode snap (default)

• geth --syncmode fast (Deprecated)

• invalid value "fast" for flag -syncmode: unknown sync mode "fast", want "full", "snap" or "light"

Related

• Ethereum nodes
• Ethereum execution layer synchronization nodes
• Ethereum consensus layer sync modes

See also

• geth --syncmode [ snap ]
• geth [ account | console | --authrpc.addr | version | --sepolia | --goerli | --pprof | --http | --syncmode | --mine ] --help, Geth logs, geth logs WARN, Log.Error, ports: 8551, 30303, 8547, ~/.ethereum/geth/

https://geth.ethereum.org/docs/fundamentals/sync-modes