WatchGuard's official VPN clients are only available for Windows and macOS, leaving Linux users in the dark. However, since WatchGuard's VPN implementation is based on OpenVPN technology, a Linux connection is technically possible through manual configuration.

To establish the connection, you'll need to extract the OpenVPN configuration from a working Windows/Mac client installation:

1. Install WatchGuard Mobile VPN on a Windows/Mac machine
2. Locate the configuration files (typically in C:\Program Files (x86)\WatchGuard\Mobile VPN or /Library/Application Support/WatchGuard/Mobile VPN)
3. Look for files with .ovpn extension or search for SSL-related certificates

You'll need these elements for your Linux OpenVPN configuration:

client
dev tun
proto udp
remote vpn.yourcompany.com 443
resolv-retry infinite
nobind
persist-key
persist-tun
remote-cert-tls server
cipher AES-256-CBC
auth SHA256
compress lz4-v2
verb 3
<ca>
-----BEGIN CERTIFICATE-----
[Your CA certificate here]
-----END CERTIFICATE-----
</ca>
<cert>
-----BEGIN CERTIFICATE-----
[Your client certificate here]
-----END CERTIFICATE-----
</cert>
<key>
-----BEGIN PRIVATE KEY-----
[Your private key here]
-----END PRIVATE KEY-----
</key>

WatchGuard VPNs typically use one of these authentication methods:

• Certificate-based authentication (shown above)
• Username/password with certificates
• Two-factor authentication

For username/password authentication, add these lines to your config:

auth-user-pass
auth-nocache

Error: TLS handshake failed
This often indicates certificate problems. Verify:

1. All certificates are properly formatted
2. The CA certificate matches the server's
3. Certificate dates are valid

Error: AUTH_FAILED
Check your authentication method matches what the server expects. Some WatchGuard implementations require special parameters:

auth-user-pass /etc/openvpn/credentials
auth-retry interact

For regular use, create a systemd service:

[Unit]
Description=WatchGuard VPN Connection
After=network.target

[Service]
Type=simple
ExecStart=/usr/sbin/openvpn --config /etc/openvpn/watchguard.conf
Restart=on-failure

[Install]
WantedBy=multi-user.target

Enable with: sudo systemctl enable watchguard-vpn

For GUI users, import the configuration into NetworkManager:

sudo nmcli connection import type openvpn file /path/to/watchguard.ovpn
sudo nmcli connection modify watchguard-vpn vpn.secrets "password=your_password"

Many sysadmins face this challenge: WatchGuard's official VPN clients only support Windows and macOS, leaving Linux users in the cold. However, since WatchGuard's VPN implementation uses OpenVPN under the hood, we can bypass this limitation with some configuration work.

The key is obtaining the OpenVPN configuration from a working Windows/Mac client installation:

1. On a Windows machine with WatchGuard VPN client installed:
   - Navigate to C:\Program Files (x86)\WatchGuard\Mobile VPN
   - Locate the *.ovpn or *.conf files

2. Alternatively, ask your network admin for:
   - Server address (FQDN or IP)
   - Authentication method (certificate, PSK, or username/password)
   - Port number (usually UDP 443 or TCP 4119)

Here's a sample OpenVPN configuration file for Linux:

client
dev tun
proto udp
remote vpn.yourcompany.com 443
resolv-retry infinite
nobind
persist-key
persist-tun
remote-cert-tls server
cipher AES-256-CBC
auth SHA256
comp-lzo no
verb 3
auth-user-pass /etc/openvpn/auth.txt
<ca>
-----BEGIN CERTIFICATE-----
[Your CA Certificate Here]
-----END CERTIFICATE-----
</ca>

WatchGuard typically uses one of these authentication schemes:

# For certificate authentication:
cert /path/to/client.crt
key /path/to/client.key

# For username/password (store in auth.txt):
username
password

Common issues and solutions:

# Check OpenVPN logs:
journalctl -u openvpn@yourconfig -f

# Verify network connectivity:
nc -zv vpn.yourcompany.com 443

# Check routing after connection:
ip route show table all

# Debug TLS handshake:
openvpn --config yourconfig.ovpn --verb 4

Create a systemd service for persistent VPN:

[Unit]
Description=WatchGuard VPN Connection
After=network.target

[Service]
Type=simple
ExecStart=/usr/sbin/openvpn --config /etc/openvpn/watchguard.ovpn
Restart=on-failure

[Install]
WantedBy=multi-user.target

Enable with: systemctl enable --now openvpn@watchguard

For complex setups, consider these options:

• Use network-manager-openvpn for GUI integration
• Configure firewall rules to match Windows client behavior
• Set up route-based VPN if policy-based fails