By default, geth implements Clique, a proof-of-authority mechanism to reach consensus. Moreover, a number of accounts a defined to produce new blocks in the chain.

A custom Ethereum testnet contains three components:

a custom [genesis file](/genesis.json
a custom data directory, which we define with GETH_DATADIR
a custom NetworkID , which we set 137

Gas

Gas refers to the unit that measures the computational effort required to execute specific operations on the Ethereum network.

Nodes

Running nodes are responsible for the following tasks:

store blockchain data,
participates in block validation (verifying blocks and states),
serve the network and provides data on request.

Storage

More details to be added soon.

Faucet

More details to be added soon.

Interacting with the client

You can run commands directly in the console:

Getting total coinbase

> web3.fromWei(eth.getBalance(eth.coinbase), "ether")

Getting a balance from an account

> web3.fromWei(eth.getBalance("2ee8D80de1c389f1254e94bc44D2d1Bc391eD402"), "ether")

txpool API

Access to several non-standard RPC methods to inspect the contents of the transaction pool containing all the currently pending transactions as well as the ones queued for future processing:

txpool

Other useful checks

admin.nodeInfo

Setting this chain on MetaMask

Click a Custom RPC network and add:

Network Name: "<project name>"
New RPC URL: localhost
Chain ID: 137

References

geth commands