# LNC Mailbox
Lightning Node Connect (LNC) is a protocol that establishes a connection between your Lightning Network node (LND) and a remote application, such as Lightning Terminal or Zeus.
To traverse firewalls and Network Address Translation (NAT), LNC makes use of a mailbox proxy. This proxy is part of the open-source aperture and can be installed freely by anybody.
LNC is most useful when both the client and the Lightning node are behind a firewall or NAT, but it can also be useful when only the Lightning node is unreachable. In this case, aperture may be installed on the same machine as the client application.
## Configure aperture
To configure aperture, we edit the configuration file.
`nano ~/.aperture/aperture.yaml`
You may use this template and don’t forget to swap the domain name with your own. This domain name should also point to the server on which you are setting up aperture!
```yaml
listenaddr: "lnc.yourlightning.app:443"
debuglevel: "trace"
autocert: true
servername: lnc.yourlightning.app
authenticator:
disable: true
hashmail:
enabled: true
messagerate: 1ms
messageburstallowance: 99999999
prometheus:
enabled: false
```
## Run aperture
To run aperture, we only need to execute one command.
`aperture`
The logs may show that aperture is now listening for connections.
`[INF] APER: Configuring autocert for server lnc.yourlightning.app with cache dir /root/.aperture/autocert`\
`[INF] APER: Starting the server, listening on lnc.yourlightning.app:443.`
## Connect to Terminal
We can now connect our LND node to Lightning Terminal using our own mailbox. You will need litd running alongside LND. Learn how to [install litd here](/lightning-network-tools/lightning-terminal/get-lit.md).
`litcli sessions add --label="My own mailbox" --type admin --mailboxserveraddr lnc.yourlightningapp:443`
Next we type the generated 10-word connection string into Lightning Terminal, together with the url and port number of our mailbox.
Connect your node to Lightning Terminal via LNC and your own proxy server
We can now connect, select and confirm a password and control our Lightning node remotely!
## Troubleshooting
On some VPS providers, aperture fails to correctly bind to the address and port it listens on.
`root@mailbox:~# aperture`\
`[INF] APER: Configuring autocert for server lnc.yourlightningapp.com with cache dir /home/ubuntu/.aperture/autocert`\
`[INF] APER: Starting the server, listening on lnc.yourlightningapp.com:443.`\
`[ERR] APER: Error while running aperture: listen tcp 172.81.180.188:443: bind: cannot assign requested address`\
`[INF] APER: Shutdown complete`
## Optional: Set up aperture with systemd
We navigate to the systemd directory and create a new service.
`cd /etc/systemd/system`\
`sudo nano aperture.service`
Here we may paste the following template
```
[Unit]
Description=LNC mailbox service
[Service]
User=ubuntu
WorkingDirectory=/home/ubuntu
ExecStart=/usr/local/bin/aperture
Restart=on-failure
RestartSec=10
[Install]
WantedBy=multi-user.target
```
To reload the list of services
`sudo systemctl daemon-reload`
To start the aperture service
`sudo systemctl start aperture.service`
To check the status of the service
`sudo systemctl status aperture.service`
---
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