neo@netkiller ~/ethereum % geth --networkid 123456 console
INFO [01-19|22:14:52] Starting peer-to-peer node instance=Geth/v1.7.3-stable-4bb3c89d/linux-amd64/go1.9.1
INFO [01-19|22:14:52] Allocated cache and file handles database=/home/neo/.ethereum/geth/chaindata cache=128 handles=1024
INFO [01-19|22:14:52] Initialised chain configuration config="{ChainID: 15 Homestead: 0 DAO: <nil> DAOSupport: false EIP150: <nil> EIP155: 0 EIP158: 0 Byzantium: <nil> Engine: unknown}"
INFO [01-19|22:14:52] Disk storage enabled for ethash caches dir=/home/neo/.ethereum/geth/ethash count=3
INFO [01-19|22:14:52] Disk storage enabled for ethash DAGs dir=/home/neo/.ethash count=2
INFO [01-19|22:14:52] Initialising Ethereum protocol versions="[63 62]" network=123456
INFO [01-19|22:14:52] Loaded most recent local header number=14 hash=70d7f1…45850a td=1966848
INFO [01-19|22:14:52] Loaded most recent local full block number=14 hash=70d7f1…45850a td=1966848
INFO [01-19|22:14:52] Loaded most recent local fast block number=14 hash=70d7f1…45850a td=1966848
INFO [01-19|22:14:52] Loaded local transaction journal transactions=0 dropped=0
INFO [01-19|22:14:52] Regenerated local transaction journal transactions=0 accounts=0
WARN [01-19|22:14:52] Blockchain not empty, fast sync disabled
INFO [01-19|22:14:52] Starting P2P networking
INFO [01-19|22:14:56] UDP listener up self=enode://9f6490ffb5236f2ddc5710ae73d47c740e0a3644bbd2d67029cf4a6c4693d2f470b642fd2cc3507f7e851df60aaeb730a1270b7a477f91ec5b6b17a8a4b40527@101.232.64.12:30303
INFO [01-19|22:14:56] RLPx listener up self=enode://9f6490ffb5236f2ddc5710ae73d47c740e0a3644bbd2d67029cf4a6c4693d2f470b642fd2cc3507f7e851df60aaeb730a1270b7a477f91ec5b6b17a8a4b40527@101.232.64.12:30303
INFO [01-19|22:14:56] IPC endpoint opened: /home/neo/.ethereum/geth.ipc
Welcome to the Geth JavaScript console!
instance: Geth/v1.7.3-stable-4bb3c89d/linux-amd64/go1.9.1
coinbase: 0x83fda0ba7e6cfa8d7319d78fa0e6b753a2bcb5a6
at block: 14 (Fri, 19 Jan 2018 21:27:16 HST)
datadir: /home/neo/.ethereum
modules: admin:1.0 debug:1.0 eth:1.0 miner:1.0 net:1.0 personal:1.0 rpc:1.0 txpool:1.0 web3:1.0
>
> INFO [01-19|22:14:56] Mapped network port proto=udp extport=30303 intport=30303 interface="UPNP IGDv1-IP1"