ETHEREUM OPTIONS¶

–syncmode value:

1. Full: Downloads all blocks (including headers, transactions and receipts)
    and generates the state of the blockchain incrementally by executing every block.
2. Fast (Default): Downloads all blocks (including headers, transactions and receipts),
    verifies all headers, and downloads the state and verifies it against the headers.
4. Light: Downloads all block headers, block data, and verifies some randomly.

实例:
$ geth --syncmode "light"

$ geth console --syncmode "light"

–networkid value [1]

// create your own private testnet.
Network identifier (integer, 1=Frontier, 2=Morden (disused), 3=Ropsten, 4=Rinkeby) (default: 1)

value是大于0的整数
1. 以太网主网(Ethereum Mainnet)
2. Expanse Network
3. Ethereum Testnet Ropsten
4. Ethereum Testnet Rinkeby