Apologies for what might be a dumb question. I have (what I think) is a private network setup with Geth initialized as follows:
geth --maxpeers 0 --nodiscover --networkid 55555 --genesis ~/g.json --datadir ~/.ethereum_experiment console
This works fine. I pre-seeded my self with Ether in my genesis JSON and was able to successfully deploy and execute the greeter contract.
What I'm confused about is what happened when I enabled mining after deploying the contract. The geth console is repeatedly finding new blocks, with logging like the following:
I0219 10:04:52.633280 25386 worker.go:448]