I have never seen these errors. Is it safe to use cli-wallet to transfer funds? Should I be concerned? Using Monero 'Wolfram Warptangent' (v0.10.0.0-release) and macOS Sierra 10.12 (16A323).
Someone is running a node that supports fluffy blocks and running on mainnet. In handshake, it's sending a request to find out if you support fluffy blocks, but current release nodes don't know about that command.