WireGuard

WireGuard is an extremely simple yet fast and modern VPN that utilizes state-of-the-art cryptography. See https://www.wireguard.com for more information.

Site to Site VPN

This diagram corresponds with the example site to site configuration below.

../../_images/wireguard_site2site_diagram.jpg

Keypairs

WireGuard requires the generation of a keypair, which includes a private key to decrypt incoming traffic, and a public key for peer(s) to encrypt traffic.

Generate Keypair

generate pki wireguard key-pair

It generates the keypair, which includes the public and private parts. The key is not stored on the system - only a keypair is generated.

vyos@vyos:~$ generate pki wireguard key-pair
Private key: iJJyEARGK52Ls1GYRCcFvPuTj7WyWYDo//BknoDU0XY=
Public key: EKY0dxRrSD98QHjfHOK13mZ5PJ7hnddRZt5woB3szyw=
generate pki wireguard key-pair install interface <interface>

Generates a keypair, which includes the public and private parts, and build a configuration command to install this key to interface.

vyos@vyos:~$ generate pki wireguard key-pair install interface wg10
"generate" CLI command executed from operational level.
Generated private-key is not stored to CLI, use configure mode commands to install key:

set interfaces wireguard wg10 private-key '4Krkv8h6NkAYMMaBWI957yYDJDMvj9URTHstdlOcDU0='

Corresponding public-key to use on peer system is: 'UxDsYT6EnpTIOKUzvMlw2p0sNOKQvFxEdSVrnNrX1Ro='

Note

If this command is invoked from configure mode with the run prefix the key is automatically installed to the appropriate interface:

vyos@vyos# run generate pki wireguard key-pair install interface wg10
"generate" CLI command executed from config session.
Generated private-key was imported to CLI!

Use the following command to verify: show interfaces wireguard wg10
Corresponding public-key to use on peer system is: '7d9KwabjLhHpJiEJeIGd0CBlao/eTwFOh6xyCovTfG8='

vyos@vyos# compare
[edit interfaces]
+wireguard wg10 {
+    private-key CJweb8FC6BU3Loj4PC2pn5V82cDjIPs7G1saW0ZfLWc=
+}
show interfaces wireguard <interface> public-key

Retrieve public key portion from configured WIreGuard interface.

vyos@vyos:~$ show interfaces wireguard wg01 public-key
EKY0dxRrSD98QHjfHOK13mZ5PJ7hnddRZt5woB3szyw=

Optional

generate pki wireguard preshared-key

An additional layer of symmetric-key crypto can be used on top of the asymmetric crypto.

This is optional.

vyos@vyos:~$ generate pki wireguard preshared-key
Pre-shared key: OHH2EwZfMNK+1L6BXbYw3bKCtMrfjpR4mCAEeBlFnRs=
generate pki wireguard preshared-key install interface <interface> peer <peer>

An additional layer of symmetric-key crypto can be used on top of the asymmetric crypto. This command automatically creates for you the required CLI command to install this PSK for a given peer.

This is optional.

vyos@vyos:~$ generate pki wireguard preshared-key install interface wg10 peer foo
"generate" CLI command executed from operational level.
Generated preshared-key is not stored to CLI, use configure mode commands to install key:

set interfaces wireguard wg10 peer foo preshared-key '32vQ1w1yFKTna8n7Gu7EimubSe2Y63m8bafz55EG3Ro='

Pre-shared key: +LuaZ8W6DjsDFJFX3jJzoNqrsXHhvq08JztM9z8LHCs=

Note

If this command is invoked from configure mode with the run prefix the key is automatically installed to the appropriate interface:

Interface configuration

The next step is to configure your local side as well as the policy based trusted destination addresses. If you only initiate a connection, the listen port and address/port is optional; however, if you act like a server and endpoints initiate the connections to your system, you need to define a port your clients can connect to, otherwise the port is randomly chosen and may make connection difficult with firewall rules, since the port may be different each time the system is rebooted.

You will also need the public key of your peer as well as the network(s) you want to tunnel (allowed-ips) to configure a WireGuard tunnel. The public key below is always the public key from your peer, not your local one.

local side - commands

  • WireGuard interface itself uses address 10.1.0.1/30
  • We only allow the 192.168.2.0/24 subnet to travel over the tunnel
  • Our remote end of the tunnel for peer to-wg02 is reachable at 192.0.2.1 port 51820
  • The remote peer to-wg02 uses XMrlPykaxhdAAiSjhtPlvi30NVkvLQliQuKP7AI7CyI= as its public key portion
  • We listen on port 51820
  • We route all traffic for the 192.168.2.0/24 network to interface wg01
set interfaces wireguard wg01 address '10.1.0.1/30'
set interfaces wireguard wg01 description 'VPN-to-wg02'
set interfaces wireguard wg01 peer to-wg02 allowed-ips '192.168.2.0/24'
set interfaces wireguard wg01 peer to-wg02 address '192.0.2.1'
set interfaces wireguard wg01 peer to-wg02 port '51820'
set interfaces wireguard wg01 peer to-wg02 public-key 'XMrlPykaxhdAAiSjhtPlvi30NVkvLQliQuKP7AI7CyI='
set interfaces wireguard wg01 port '51820'

set protocols static route 192.168.2.0/24 interface wg01

The last step is to define an interface route for 192.168.2.0/24 to get through the WireGuard interface wg01. Multiple IPs or networks can be defined and routed. The last check is allowed-ips which either prevents or allows the traffic.

Warning

You can not assign the same allowed-ips statement to multiple WireGuard peers. This a design decision. For more information please check the WireGuard mailing list.

set interfaces wireguard <interface> private-key <name>

To use a named key on an interface, the option private-key needs to be set.

set interfaces wireguard wg01 private-key KP01

The command show wireguard keypairs pubkey KP01 will then show the public key, which needs to be shared with the peer.

remote side - commands

set interfaces wireguard wg01 address '10.1.0.2/30'
set interfaces wireguard wg01 description 'VPN-to-wg01'
set interfaces wireguard wg01 peer to-wg01 allowed-ips '192.168.1.0/24'
set interfaces wireguard wg01 peer to-wg01 address '192.0.2.2'
set interfaces wireguard wg01 peer to-wg01 port '51820'
set interfaces wireguard wg01 peer to-wg01 public-key 'u41jO3OF73Gq1WARMMFG7tOfk7+r8o8AzPxJ1FZRhzk='
set interfaces wireguard wg01 port '51820'

set protocols static route 192.168.1.0/24 interface wg01

Firewall Exceptions

For the WireGuard traffic to pass through the WAN interface, you must create a firewall exception.

set firewall name OUTSIDE_LOCAL rule 10 action accept
set firewall name OUTSIDE_LOCAL rule 10 description 'Allow established/related'
set firewall name OUTSIDE_LOCAL rule 10 state established enable
set firewall name OUTSIDE_LOCAL rule 10 state related enable
set firewall name OUTSIDE_LOCAL rule 20 action accept
set firewall name OUTSIDE_LOCAL rule 20 description WireGuard_IN
set firewall name OUTSIDE_LOCAL rule 20 destination port 51820
set firewall name OUTSIDE_LOCAL rule 20 log enable
set firewall name OUTSIDE_LOCAL rule 20 protocol udp
set firewall name OUTSIDE_LOCAL rule 20 source

You should also ensure that the OUTISDE_LOCAL firewall group is applied to the WAN interface and a direction (local).

set interfaces ethernet eth0 firewall local name 'OUTSIDE-LOCAL'

Assure that your firewall rules allow the traffic, in which case you have a working VPN using WireGuard.

wg01# ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=1.16 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=1.77 ms

wg02# ping 192.168.2.1
PING 192.168.2.1 (192.168.2.1) 56(84) bytes of data.
64 bytes from 192.168.2.1: icmp_seq=1 ttl=64 time=4.40 ms
64 bytes from 192.168.2.1: icmp_seq=2 ttl=64 time=1.02 ms

An additional layer of symmetric-key crypto can be used on top of the asymmetric crypto. This is optional.

vyos@vyos:~$ generate pki wireguard preshared-key install
rvVDOoc2IYEnV+k5p7TNAmHBMEGTHbPU8Qqg8c/sUqc=

Copy the key, as it is not stored on the local filesystem. Because it is a symmetric key, only you and your peer should have knowledge of its content. Make sure you distribute the key in a safe manner,

wg01# set interfaces wireguard wg01 peer to-wg02 preshared-key 'rvVDOoc2IYEnV+k5p7TNAmHBMEGTHbPU8Qqg8c/sUqc='
wg02# set interfaces wireguard wg01 peer to-wg01 preshared-key 'rvVDOoc2IYEnV+k5p7TNAmHBMEGTHbPU8Qqg8c/sUqc='

Remote Access “RoadWarrior” Example

With WireGuard, a Road Warrior VPN config is similar to a site-to-site VPN. It just lacks the address and port statements.

In the following example, the IPs for the remote clients are defined in the peers. This allows the peers to interact with one another.

wireguard wg0 {
    address 10.172.24.1/24
    address 2001:db8:470:22::1/64
    description RoadWarrior
    peer MacBook {
        allowed-ips 10.172.24.30/32
        allowed-ips 2001:db8:470:22::30/128
        persistent-keepalive 15
        pubkey F5MbW7ye7DsoxdOaixjdrudshjjxN5UdNV+pGFHqehc=
    }
    peer iPhone {
        allowed-ips 10.172.24.20/32
        allowed-ips 2001:db8:470:22::20/128
        persistent-keepalive 15
        pubkey BknHcLFo8nOo8Dwq2CjaC/TedchKQ0ebxC7GYn7Al00=
    }
    port 2224
}

The following is the config for the iPhone peer above. It’s important to note that the AllowedIPs wildcard setting directs all IPv4 and IPv6 traffic through the connection.

[Interface]
PrivateKey = ARAKLSDJsadlkfjasdfiowqeruriowqeuasdf=
Address = 10.172.24.20/24, 2001:db8:470:22::20/64
DNS = 10.0.0.53, 10.0.0.54

[Peer]
PublicKey = RIbtUTCfgzNjnLNPQ/ulkGnnB2vMWHm7l2H/xUfbyjc=
AllowedIPs = 0.0.0.0/0, ::/0
Endpoint = 192.0.2.1:2224
PersistentKeepalive = 25

However, split-tunneling can be achieved by specifying the remote subnets. This ensures that only traffic destined for the remote site is sent over the tunnel. All other traffic is unaffected.

[Interface]
PrivateKey = 8Iasdfweirousd1EVGUk5XsT+wYFZ9mhPnQhmjzaJE6Go=
Address = 10.172.24.30/24, 2001:db8:470:22::30/64

[Peer]
PublicKey = RIbtUTCfgzNjnLNPQ/ulkGnnB2vMWHm7l2H/xUfbyjc=
AllowedIPs = 10.172.24.30/24, 2001:db8:470:22::/64
Endpoint = 192.0.2.1:2224
PersistentKeepalive = 25

Operational Commands

Status

show interfaces wireguard wg0 summary

Show info about the Wireguard service. It also shows the latest handshake.

vyos@vyos:~$ show interfaces wireguard wg0 summary
interface: wg0
  public key:
  private key: (hidden)
  listening port: 51820

peer: <peer pubkey>
  endpoint: <peer public IP>
  allowed ips: 10.69.69.2/32
  latest handshake: 23 hours, 45 minutes, 26 seconds ago
  transfer: 1.26 MiB received, 6.47 MiB sent
show interfaces wireguard

Get a list of all wireguard interfaces

Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface        IP Address                        S/L  Description
---------        ----------                        ---  -----------
wg0              10.0.0.1/24                       u/u
show interfaces wireguard <interface>

Show general information about specific WireGuard interface

vyos@vyos:~$ show interfaces wireguard wg01
interface: wg0
  address: 10.0.0.1/24
  public key: h1HkYlSuHdJN6Qv4Hz4bBzjGg5WUty+U1L7DJsZy1iE=
  private key: (hidden)
  listening port: 41751

    RX:  bytes  packets  errors  dropped  overrun       mcast
             0        0       0        0        0           0
    TX:  bytes  packets  errors  dropped  carrier  collisions
             0        0       0        0        0           0

Remote Access “RoadWarrior” clients

Some users tend to connect their mobile devices using WireGuard to their VyOS router. To ease deployment one can generate a “per mobile” configuration from the VyOS CLI.

Warning

From a security perspective, it is not recommended to let a third party create and share the private key for a secured connection. You should create the private portion on your own and only hand out the public key. Please keep this in mind when using this convenience feature.

generate wireguard client-config <name> interface <interface> server <ip|fqdn> address <client-ip>

Using this command, you will create a new client configuration which can connect to interface on this router. The public key from the specified interface is automatically extracted and embedded into the configuration.

The command also generates a configuration snipped which can be copy/pasted into the VyOS CLI if needed. The supplied <name> on the CLI will become the peer name in the snippet.

In addition you will specifiy the IP address or FQDN for the client where it will connect to. The address parameter can be used up to two times and is used to assign the clients specific IPv4 (/32) or IPv6 (/128) address.

WireGuard Client QR code