Do not use the GUI in the `sys-bitcoin` qube to edit configuration, it won't
persist and `bitcoin-qt` cannot be run at the same time as `bitcoind`.
You can use the GUI in the `bitcoin` qube, specially useful for an easy-to-use
interface for the Bitcoin Core Wallet.
### Connect to a remote Bitcoin RPC
#### Evaluation of remote Bitcoin RPC
You may wish to connect to a remote Bitcoin node with RPC available to:
- Lower disk space usage and to lower resource consumption by not having
multiple Bitcoin blockchains;
- Avoid changing scripts and configurations that expect the connection to be
working on `127.0.0.1:8332`, such as the Qrexec policy for connecting
Bitcoind RPC to the Electrum Servers.
But there are huge disadvantages to this method:
- [Bitcoin Core RPC does not have transport encryption](https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-0.12.0.md#rpc-ssl-support-dropped).
Therefore, this method is advised against unless you know how to enable
transport encryption to connect to your Bitcoin RPC. If you run bitcoind on
`sys-bitcoin`, you do not have to worry about transport encryption as
communication is done securely via Qrexec.
- Bitcoin configuration cannot be changed remotely, therefore adding RPC
Authentication for clients such as Electrum Servers have to be done
manually.
The remote bitcoind setup is difficult to fit all user needs and requires you
to change a remote node we have no control over the configuration, therefore,
it is intended for advanced users only.
#### Configure the remote node
On the remote node:
- You must set in the node's `bitcoin.conf`, the following options to bind to
the external interface: `rpcbind`, `bind` (Electrs),
`whitelist=download@<ADDR>` (ElectRS), `zmqpubhashblock` (Fulcrum) and allow
connections of the external IP of your upstream netvm via `rpcallowip`.
- Open the configured ports of the previous settings in the firewall to be
reachable by the Qubes system.
- Generate RPC credentials (see `bitcoin/share/rpcauth/rpcauth.py`), add
`rpcauth=` option to `bitcoin.conf` and save the `user` and `password` for
later.
- Restart bitcoind to apply the configuration changes.
#### Connect the qube to the remote node
**Warning**: use of `sys-bitcoin` for the remote node connection is
discouraged as you either need to expose the node RPC port to an onion service
(preferably with Onion Authentication) or punch a hole in the Whonix firewall
so it can reach your LAN.
The following example uses the qube `sys-net` as a netvm that can connect
to your remote node running on the address `192.168.2.10`, RPC port `8332`,
P2P port `8333`, ZMQPUBHASHBLOCK port `8433`.
In `dom0`, create the user Qrexec policy to target the qube `sys-net` in
