Running the quorum command on a stellar-core node will presumably show the current node ID. The node ID looks like a stellar public account key.
How is this assigned? Is the similarity to a public account key just coincidental?
Each node has it's own unique NODE_SEED which is used for messages signing. It can be set in the config file. The seed used for generating the public key this node will be identified with in SCP (that's a node ID you mentioned).
If you don't specify the NODE_SEED parameter explicitly, it will be generated randomly on each startup.
To generate a new, stable seed (and associated public key), run:
stellar-core --genseed
Public key can be obtained from the seed by running:
stellar-core --convertid <your_seed>
Once you generated a stable seed, add it to your stellar.cfg file:
NODE_SEED="SBJ23H4G5G4D2352D34G523G4L343455D23G4D43GF5DKL self"
