By connecting both a computer on the internal LAN and various clients to a centralized VPS with a static IP, we can use WireGuard to access a local network behind a permanent NAT/Firewall. WireGuard provides a fast and simple VPN protocol which works well for this situation. However, it should be noted that WireGuard is still under heavy development and has not undergone security audits. I would recommend reading more about WireGuard, particularly the “Conceptual Overview” here:, before trying this example.

For this example, I will refer to the following three clients. Although our VPS acts as a “server”, each computer is considered a client by WireGuard.

  • A local client on the desired LAN (such as Pi)
    • “lan”
    • Wireguard IP:
    • Local IP:
    • Running Ubuntu for Pi 18.04 LTS
  • A VPS (or similar) accessible with a static IP
    • “vps”
    • Wireguard IP:
    • Public IP: Accessible URL
    • Running Ubuntu 18.04 LTS
  • Multiple clients for remote access
    • “laptop”
    • Wireguard IP:
    • Local IP: Any DHCP Address
    • Running Mac or Windows

For reference, the local network is on while the WireGuard clients are on These can and should be adjusted as necessary.

Installing WireGuard and Configuring the System

Information about the installation of WireGuard for specific systems is available at When used from the command line, a WireGuard interface can be created using either wg or wg-quick. wg-quick has a few features such as automatic routing, which will be utilized in this example. GUI clients have also worked fine in my testing.

The VPS and LAN client will need IP forwarding enabled. First check if it is enabled by running the following command a getting an output of 0 (disabled) or 1 (enabled):

sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 1

If disabled by default, it can sometimes be helpful to temporarily enable IP forwarding for testing with this command.

sysctl -w net.ipv4.ip_forward=1

To enable IP forwarding permanently we can add the following line to /etc/sysctl.conf and restart the system.


Finally, we need to create a directory for our WireGuard configurations.

mkdir /etc/wireguard
cd /etc/wireguard

Generating Keys

WireGuard uses a public/private key pair to encrypt packets sent along the interface. On each client needs to locally generate a key pair using wg genkey and wg pubkey. GUI clients will create these automatically, but in a terminal, you can quickly save them to files with the following command.

umask 077 # Prevent credential leak
wg genkey | tee privatekey | wg pubkey > publickey

I recommend saving them in the save directory as your configuration files, /etc/wireguard. Now would also be a good time to secure this directory so that it is only accessible by root.

sudo chown -R root:root /etc/wireguard/
sudo chmod -R og-rwx /etc/wireguard/*

Configuring WireGuard

wg-quick uses simple configuration files to create each WireGuard interface. Create a configuration in /etc/wireguard or through the GUI. Configuration files should be named whatever you want to call the wireguard interface, generally wg0.conf or wg1.conf. Below are the three configurations used in this example.

LAN configuration
Address =
PrivateKey = <lan private key>
PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -A FORWARD -o %i -j ACCEPT; iptables -t nat -A POSTROUTING -o <lan interface (eth0)> -j MASQUERADE
PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -D FORWARD -o %i -j ACCEPT; iptables -t nat -D POSTROUTING -o <lan interface (eth0)> -j MASQUERADE

PublicKey = <vps public key>
Endpoint = <vps ip>:51820
AllowedIPs =

PersistentKeepalive = 25
VPS Configuration
Address =
PrivateKey = <vps private key>
ListenPort = 51820

PublicKey = <lan public key>
AllowedIPs =,

PublicKey = <laptop public key>
AllowedIPs =
Laptop Configuration
PrivateKey = <laptop private key>
Address =

PublicKey = <vps public key>
AllowedIPs =
Endpoint = <vps ip>:51820

PersistentKeepalive = 25

Although generally straightforward, a few of these entries deserve some explanation.

  • PostUp and PostDown on the LAN client create the necessary routing rules to allow traffic to pass between the local and vpn networks. There are other routing rules required, but wg-quick should take care of them.
  • The Endpoint and PersistentKeepalive entries on the Laptop and LAN clients is what allows them to communicate from behind a NAT. Endpoint initiates a direct connection to the VPS, while PersistentKeepalive keeps them in communication from behind any router. In this case it refreshes the link every 25 seconds.
  • AllowedIPs controls which devices or networks can communicate over an interface. WireGuard uses this to setup routing rules as well as which connections to allow or drop. If you expect a peer to send or receive packets from a client or network, it should be included in its AllowedIPs.

Testing the Network

To initialize an interface run simply run the following command, replacing wg0 with your interface if necessary.

wg-quick up wg0

After starting the interface on each device, check the status of each using the wg command. You should see an output like this on the VPS:

interface: wg0
  public key: <vps public key>
  private key: (hidden)
  listening port: 51820

peer: <lan public key>
  endpoint: <lan public ip>:<random port>
  allowed ips:,,
  latest handshake: 39 seconds ago
  transfer: 1.97 MiB received, 337.50 KiB sent

peer: <laptop public key>
  endpoint: <laptop public ip>:<random port>
  allowed ips:
  latest handshake: 1 minute, 7 seconds ago
  transfer: 353.60 KiB received, 1.97 MiB sent

Finally, check to see if the laptop can access all clients as well as something on the LAN by sending a ping to and 10.10.1.x.

Firewall Configuration

Generally, it is a good idea to have a firewall setup on your computer. Given the wide variety of situations, I cannot recommend one certain setup, but can provide one option.


If on Ubuntu, ufw is the easiest way to configure a basic firewall. Digital ocean has a good guide to getting one setup and allowing SSH connections.

I can’t figure out how to use ufw while allowing wireguard to forward. Let me know if you can, please.


Using FirewallD and CentOS, we can configure a basic firewall using firewall-cmd. Probably the easiest way to allow connections through WireGuard, while still maintaining some level of outside security is to set the eth0 and wg0 interfaces to different zones with different rules. By default, eth0 exists on the public zone, and you can change wg0 to the home zone with this command.

firewall-cmd --permanent --zone=home --change-interface=wg0

Anything configured in the home zone will then affect traffic passing through the VPN. This can be configured on a case-by-case basis, or you can enable all traffic with this command.

firewall-cmd --permanent --zone=home --set-target=ACCEPT

While we’re on the topic of security, remember to enable automatic updates on all the computers!

Running WireGuard as a Service

If everything goes well, you can setup WireGuard as a service on the LAN and VPS clients so that is starts on boot with the command below. Make sure to permanently enable IP forwarding also.

systemctl enable [email protected]

Go ahead and restart each computer, then verify that the connection still works.

Setting up Pi-Hole

Pi-Hole is an easy way to block ads and create custom DNS and DHCP for the local netowrk. It is probably the easiest way to automatically use custom domain names with remote clients.

The Pi-Hole website provides instructions for a basic installation. In addition, the following settings should be changed under the settings tab.

  • DHCP server enabled
  • Listen on all interfaces, permit all origins
  • Pi-Hole domain name: lan (allows devices to be accessed with hostname.lan)

Diagnosing Connections

If you encounter problems making a connection, try checking some of these common problems:

WireGuard interface doesn’t start
  • If using a GUI, run from the command line to check for configuration errors.
  • Use -v to see additional information.
Cannot ping other clients or no handshake
  • Check that the VPS public IP is visible.
  • Verify that each public/private key pair is correct in each configuration.
  • Check the wg-quick output for configuration errors.
Cannot access LAN computers
  • Ensure that the local computer is on and accepting ping by something on the local network.
  • Check that IP forwarding is enabled on both the VPS and the LAN (sysctl net.ipv4.ip_forward).
  • Make sure the laptop can ping the LAN client in the first place.
  • Check routing on all computers while wg-quick is active.
Can ping LAN but cannot connect and services or ports
  • Make sure that the VPS firewall is allowing connections through, and not blocking all ports.
Can access IPs but no domain name resolution
  • DNS resolution required additional DHCP configuration on your router or DHCP server.
  • Running Pi-Hole as a DHCP server on the LAN device seems to be the fastest way to enable this.
  • Add the Pi-Hole IP to the OS DNS table or in WireGuard’s Interface configuration.
  • Allow DNS resolution for all devices in Pi-Hole.
Helpful Diagnostic Tools
  • tcpdump for checking what packets each computer is receiving.
  • traceroute to check how packets are being routed within the network.
  • route and ip route to show any configured static routes.
  • nmap to scan for open ports on a device, or devices on a given subnet.

Additional Resources

Here are a couple of websites with additional information which might be helpful.