From the WireGuard project homepage:
- Wireguard is an extremely simple yet fast and modern VPN that utilizes state-of-the-art cryptography. It aims to be faster, simpler, leaner, and more useful than IPSec, while avoiding the massive headache. It intends to be considerably more performant than OpenVPN. WireGuard is designed as a general purpose VPN for running on embedded interfaces and super computers alike, fit for many different circumstances. Initially released for the Linux kernel, it plans to be cross-platform and widely deployable. It is currently under heavy development, but already it might be regarded as the most secure, easiest to use, and simplest VPN solution in the industry.
- 1 Installation
- 2 Usage
- 3 Setup a VPN server
- 4 Troubleshooting
- 5 Tips and tricks
Install the package.
To create a public and private key on a peer:
$ wg genkey | tee privatekey | wg pubkey > publickey
Below commands will demonstrate how to setup a basic tunnel between two peers with the following settings:
|Peer A||Peer B|
|External IP address||10.10.10.1/24||10.10.10.2/24|
|Internal IP address||10.0.0.1/24||10.0.0.2/24|
|wireguard listening port||UDP/48574||UDP/39814|
The external addresses should already exist. For example, peer A should be able to ping peer B via
ping 10.10.10.2, and vice versa. The internal addresses will be new addresses created by the
ip commands below and will be shared internally within the new WireGuard network. The
/24 in the IP addresses is the CIDR.
Peer A setup
This peer will listen on UDP port 48574 and will accept connection from peer B by linking its public key with both its inner and outer IPs addresses.
# ip link add dev wg0 type wireguard # ip addr add 10.0.0.1/24 dev wg0 # wg set wg0 listen-port 48574 private-key ./privatekey # wg set wg0 peer [Peer B public key] persistent-keepalive 25 allowed-ips 10.0.0.2/32 endpoint 10.10.10.2:39814 # ip link set wg0 up
[Peer B public key] should have the same format as
allowed-ips is a list of addresses that peer A will be able to send traffic to.
allowed-ips 0.0.0.0/0 would allow sending traffic to any address.
Peer B setup
As with Peer A, whereas the wireguard daemon is listening on the UDP port 39814 and accept connection from peer A only.
# ip link add dev wg0 type wireguard # ip addr add 10.0.0.2/24 dev wg0 # wg set wg0 listen-port 39814 private-key ./privatekey # wg set wg0 peer [Peer A public key] persistent-keepalive 25 allowed-ips 10.0.0.1/32 endpoint 10.10.10.1:48574 # ip link set wg0 up
Invoking the wg command without parameter will give a quick overview of the current configuration.
As an example, when Peer A has been configured we are able to see its identity and its associated peers:
peer-a$ wg interface: wg0 public key: UguPyBThx/+xMXeTbRYkKlP0Wh/QZT3vTLPOVaaXTD8= private key: (hidden) listening port: 48574 peer: 9jalV3EEBnVXahro0pRMQ+cHlmjE33Slo9tddzCVtCw= endpoint: 10.10.10.2:39814 allowed ips: 10.0.0.2/32
At this point one could reach the end of the tunnel:
peer-a$ ping 10.0.0.2
The config can be saved by utilizing
# wg showconf wg0 > /etc/wireguard/wg0.conf # wg setconf wg0 /etc/wireguard/wg0.conf
Example peer configuration
[Interface] PrivateKey = [CLIENT PRIVATE KEY] [Peer] PublicKey = [SERVER PUBLICKEY] AllowedIPs = 10.0.0.0/24, 10.123.45.0/24, 1234:4567:89ab::/48 Endpoint = [SERVER ENDPOINT]:51820 PersistentKeepalive = 25
Setup a VPN server
Wireguard comes with a tool to quickly create and tear down VPN servers and clients,
wg-quick. Note that the config file used here is not a valid config file that can be used with
wg setconf, and that you'll possibly have to change at least the interface from
eth0 to the one you use.
[Interface] Address = 10.0.0.1/24 # This is the virtual IP address, with the subnet mask we will use for the VPN PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -A FORWARD -o %i -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -D FORWARD -o %i -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE ListenPort = 51820 PrivateKey = [SERVER PRIVATE KEY] [Peer] PublicKey = [CLIENT PUBLIC KEY] AllowedIPs = 10.0.0.2/32 # This denotes the clients IP with a /32: the client only has ONE IP.
In order for the iptables rules to work, IPv4 forwarding should be enabled:
# sysctl net.ipv4.ip_forward=1
To make the change permanent, add
net.ipv4.ip_forward = 1 to
Bring the interface up by using
wg-quick up wg0server, and use
wg-quick down wg0server to bring it down.
Client (tunnel all traffic)
[Interface] Address = 10.0.0.2/24 # The client IP from wg0server.conf with the same subnet mask PrivateKey = [CLIENT PRIVATE KEY] DNS = 10.0.0.1 [Peer] PublicKey = [SERVER PUBLICKEY] AllowedIPs = 0.0.0.0/0, ::0/0 Endpoint = [SERVER ENDPOINT]:51820 PersistentKeepalive = 25
Bring this interface up by using
wg-quick up wg0, and use
wg-quick down wg0 to bring it down.
To bring this up automatically one can use
systemctl enable wg-quick@wg0
If you use NetworkManager, it may be necessary to also enable NetworkManager-wait-online.service
systemctl enable NetworkManager-wait-online.service
or if you're using systemd-networkd, to enable systemd-networkd-wait-online.service
systemctl enable systemd-networkd-wait-online.service
to wait until devices are network ready before attempting wireguard connection.
DKMS module not available
If the following command does not list any module after you installed,
$ modprobe wireguard && lsmod | grep wireguard
or if creating a new link returns
# ip link add dev wg0 type wireguard RTNETLINK answers: Operation not supported
you probably miss the linux headers.
These headers are available inor depending of the kernel installed on your system.
Routes are periodically reset
Make sure that NetworkManager is not managing your Wireguard interface:
Connection loss with NetworkManager
On desktop, connection loss can be experienced when all the traffic is tunnelled through a Wireguard interface: typically, the connection is seemingly lost after a while or upon new connection to an access point.
wg-quick uses a resolvconf provider such as openresolv to register new DNS entries (i.e.
DNS keyword in the configuration file). However NetworkManager does not use resolvconf by default: every time a new DHCP lease is acquired, NetworkManager overwrites the global DNS addresses with the DHCP-provided ones which might not be available through the tunnel.
If resolvconf is already used by the system and you still experience connection loss, make sure NetworkManager is configured to use it: NetworkManager#Use_openresolv.
See Dnsmasq#openresolv for configuration.
At the time of writing (Sept. 2018), the resolvconf-compatible mode offered by
systemd-resolved can still be used by
wg-quick through the
PostUp hook. First make sure that NetworkManager is configured with
systemd-resolved: NetworkManager#systemd-resolved and then alter the tunnel configuration:
[Interface] Address = 10.0.0.2/24 # The client IP from wg0server.conf with the same subnet mask PrivateKey = [CLIENT PRIVATE KEY] PostUp = resolvectl domain %i "~."; resolvectl dns %i 10.0.0.1; resolvectl dnssec %i yes [Peer] PublicKey = [SERVER PUBLICKEY] AllowedIPs = 0.0.0.0/0, ::0/0 Endpoint = [SERVER ENDPOINT]:51820 PersistentKeepalive = 25
"~." as a domain name is necessary for
systemd-resolved to give priority to the newly available DNS server.
PostDown key is necessary as
systemd-resolved automatically revert all parameters when
wg0 is torn down.
Tips and tricks
Store private keys in encrypted form
It may be desirable to store private keys in encrypted form, such as through use of. Just replace the PrivateKey line under [Interface] in your config file with:
PostUp = wg set %i private-key <(su user -c "export PASSWORD_STORE_DIR=/path/to/your/store/; pass WireGuard/private-keys/%i")
where user is your username. See the
wg-quick(8) man page for more details.