The Nym Mixnodes were built in the Installation section. If you haven’t yet built Nym and want to run the code, go there first.
You can run the Mix Node from the
nym top-level directory like this:
You should get a welcome message:
nym$ target/release/nym-mixnode _ __ _ _ _ __ ___ | '_ \| | | | '_ \ _ \ | | | | |_| | | | | | | |_| |_|\__, |_| |_| |_| |___/ (mixnode - version 0.5.0) usage: --help to see available options.
Mixnodes accept Sphinx packets, shuffle packets together, and forward them onwards.
On receipt of a packet, the mixnode unwraps a layer of Sphinx encryption and assigns a delay timer based on information inside the unwrapped packet header. When the timer expires, the node forwards the packet payload (which is another Sphinx packet) to its next destination based on the routing information in the packet header. The process repeats, with layer-encrypted Sphinx packets being progressively unwrapped and forwarded, until the packet gets to its destination. The shuffling together of lots of packets within the nodes is what provides privacy to users.
Routing and delay information is chosen by the client, rather than by mixnodes.
target/release/nym-mixnode --help provides a list of available commands. You can always see help info for a given subcommand by doing
target/release/nym-mixnode <commandname> --help
target/release/nym-mixnode init --help
init command saves a configuration file to disk. You must supply 3 parameters:
--ida name for this mixnode (determines where the config file will be saved, keep it to one word)
--hostneeds to be an IPv4 or IPv6 address. If you’re planning to join the testnet, you’ll need to make sure this address is routable from the open internet. Hostnames also work but they need to be resolvable at the time you
--layerneeds to be an integer (1, 2, or 3) to assign the mixnode to a layer in the network topology. This option will go away in a few weeks, as we’re working on having the system assign layer automatically according to need.
If you’d like, you can add in:
--locationan OPTIONAL parameter that tells us where your node is located. Helpful for tracking distances between nodes, which can tell us a bit about latency.
target/release/nym-mixnode init --id baby-yoda --host 220.127.116.11 --layer 1 --location London
nym$ target/release/nym-mixnode init --id baby-yoda --host 18.104.22.168 --layer 1 --location London _ __ _ _ _ __ ___ | '_ \| | | | '_ \ _ \ | | | | |_| | | | | | | |_| |_|\__, |_| |_| |_| |___/ (mixnode - version 0.5.0) Initialising mixnode baby-yoda... 2020-03-20T11:19:41.721 INFO pemstore::pemstore > Written private key to "~/.nym/mixnodes/baby-yoda/data/private_sphinx.pem" 2020-03-20T11:19:41.721 INFO pemstore::pemstore > Written public key to "~/.nym/mixnodes/baby-yoda/data/public_sphinx.pem" Saved mixnet sphinx keypair Saved configuration file to "~/.nym/mixnodes/baby-yoda/config/config.toml" Mixnode configuration completed.
Have a look at the saved configuration files to see more configuration options.
If you want to run a mixnode locally, you can run a local directory server on http://127.0.0.1:8080 and bind to your loopback address (127.0.0.1) or
You’ll see a startup warning whenever you bind to your loopback address, because you won’t be routable for clients out on the big internet.
However, if you are attempting to join the Nym testnet, your
--host parameter must contain a publicly routable internet address.
target/release/nym-mixnode run command runs a mixnode.
target/release/nym-mixnode run --id baby-yoda
nym$ ./target/release/nym-mixnode run --id baby-yoda _ __ _ _ _ __ ___ | '_ \| | | | '_ \ _ \ | | | | |_| | | | | | | |_| |_|\__, |_| |_| |_| |___/ (mixnode - version 0.5.0) Starting mixnode... Public key: rbl74MfQ-xVqtBIOq2coPGWxNztlqNDqP0R0kLB9p2g= Directory server: https://directory.nymtech.net Listening for incoming packets on 22.214.171.124:1789 Announcing the following socket address: 126.96.36.199:1789
./target/release/nym-mixnode help run shows available options.
On some services (e.g. AWS, Google), the machine’s available bind address is not the same as the public IP address. In this case, bind
--host to the local machine address returned by
ifconfig, but also specify
--announce-host with the public IP. Please make sure that you pass the correct, routable
For example, on a Google machine, you may see the following output from the
ens4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1460 inet 10.126.5.7 netmask 255.255.255.255 broadcast 0.0.0.0 ...
ens4 interface has the IP
10.126.5.7. But this isn’t the public IP of the machine, it’s the IP of the machine on Google’s internal network. The public IP of this machine is something else, e.g.
188.8.131.52 as set by AWS.
nym-mixnode init --host 10.126.5.7 --layer 1, starts the mixnode, but no packets will be routed because
10.126.5.7 is not on the public internet.
nym-mixnode init --host 184.108.40.206 --layer 1, you’ll get back a startup error saying
AddrNotAvailable. This is because the mixnode doesn’t know how to bind to a host that’s not in the output of
The right thing to do in this situation is
nym-mixnode init --host 10.126.5.7 --announce-host 220.127.116.11 --layer 1.
This will bind the mixnode to the available host
10.126.5.7, but announce the mixnode’s public IP to the directory server as
18.104.22.168. It’s up to you as a node operator to ensure that your public and private IPs match up properly.
In general, we want to run a mixnet that’s 3 layers deep for out testnet. Have a look at the Nym testnet dashboard, and slot yourself into layer 1, 2, or 3. If you’re running IPv6, please pick layer 2 or layer 3, as a lot of consumer clients still do not fully support IPv6 and may not be able to talk to your nodes.
We are currently working to eliminate the need for you to choose a layer - the system itself will soon do the job automatically.
Once you’ve started your mixnode, it will automatically show up in the Nym testnet dashboard unless you’ve specified a different directory server.