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

Configuration

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 wireguard keypair
It generates the keypair, which includes the public and private parts, and stores it within VyOS. It will be used per default on any configured WireGuard interface, even if multiple interfaces are being configured.
show wireguard pubkey

It shows the public key to be shared with your peer(s). Your peer will encrypt all traffic to your system using this public key.

vyos@vyos:~$ show wireguard pubkey
hW17UxY7zeydJNPIyo3UtGnBHkzTK/NeBOrDSIU9Tx0=

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 as 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

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 endpoint '<Site1 Pub IP:51820>
set interfaces wireguard wg01 peer to-wg02 pubkey 'XMrlPykaxhdAAiSjhtPlvi30NVkvLQliQuKP7AI7CyI='
set interfaces wireguard wg01 port '51820'
set protocols static route 192.168.2.0/24 interface wg01

local side - annotated commands

set interfaces wireguard wg01 address '10.1.0.1/30'                      # Address of the wg01 tunnel interface.
set interfaces wireguard wg01 description 'VPN-to-wg02'
set interfaces wireguard wg01 peer to-wg02 allowed-ips '192.168.2.0/24'  # Subnets that are allowed to travel over the tunnel
set interfaces wireguard wg01 peer to-wg02 endpoint '<Site1 Pub IP:51820>
set interfaces wireguard wg01 peer to-wg02 pubkey '<pubkey>'             # Public Key of the Peer
set interfaces wireguard wg01 port '51820'                               # Port of own server
set protocols static route 192.168.2.0/24 interface wg01                 # Static route to remote subnet

The last step is to define an interface route for 10.2.0.0/24 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.

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-wg02 allowed-ips '192.168.1.0/24'
set interfaces wireguard wg01 peer to-wg02 endpoint '<Site1 Pub IP:51820>
set interfaces wireguard wg01 peer to-wg02 pubkey 'u41jO3OF73Gq1WARMMFG7tOfk7+r8o8AzPxJ1FZRhzk='
set interfaces wireguard wg01 port '51820'
set protocols static route 192.168.1.0/24 interface wg01

remote side - annotated commands

set interfaces wireguard wg01 address '10.1.0.2/30'                     # Address of the wg01 tunnel interface.
set interfaces wireguard wg01 description 'VPN-to-wg01'
set interfaces wireguard wg01 peer to-wg02 allowed-ips '192.168.1.0/24' # Subnets that are allowed to travel over the tunnel
set interfaces wireguard wg01 peer to-wg02 endpoint '<Site1 Pub IP:51820>
set interfaces wireguard wg01 peer to-wg02 pubkey '<pubkey>'            # Public key of the Peer
set interfaces wireguard wg01 port '51820'                              # Port of own server
set protocols static route 192.168.1.0/24 interface wg01                # Static route to remote subnet

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.

wg01# run generate wireguard preshared-key
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 specifing 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

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

Encryption Keys

show wireguard keypair pubkey <name>

Show public key portion for specified key. This can be either the default key, or any other named key-pair.

The default keypair

vyos@vyos:~$ show wireguard keypair pubkey default
FAXCPb6EbTlSH5200J5zTopt9AYXneBthAySPBLbZwM=

Name keypair KP01

vyos@vyos:~$ show wireguard keypair pubkey KP01
HUtsu198toEnm1poGoRTyqkUKfKUdyh54f45dtcahDM=
delete wireguard keypair pubkey <name>

Delete a keypair, this can be either the default key, or any other named key-pair.

vyos@vyos:~$ delete wireguard keypair default