blockchain//wallet//network

A network, in a wallet such as Metamask, is the blockchain the wallet connects to, defined by an RPC endpoint URL and a chain ID, so switching networks means changing those two values. The chain ID tells Metamask which blockchain it signs for, which is what gives a transaction its replay protection. Metamask has no knowledge of Docker networks: it only understands RPC URLs and `chainId` values.

A network, in a wallet such as Metamask, is the blockchain the wallet connects to, defined by an RPC endpoint URL and a chain ID, so switching networks means changing those two values. The chain ID tells Metamask which blockchain it signs for, which is what gives a transaction its replay protection. Metamask has no knowledge of Docker networks: it only understands RPC URLs and chainId values.

Connecting to a local Besu node means adding a custom network with http://localhost:9999 and the chainId from the genesis file. DApps such as Uniswap fail on local networks, because their smart contracts do not exist there (it is a different chain).