CGNAT (Carrier-Grade NAT) can hinder port forwarding and direct connectivity when using ExpressVPN. Bypassing it in Nordic countries (where available) often involves alternative VPN protocols and configurations.
CGNAT places multiple customers behind a single public IP address, preventing direct inbound connections.
This impacts services like game servers, self-hosted applications, and remote access.
ExpressVPN, by default, doesn't offer dedicated public IPs, necessitating workarounds.
Protocol Switching:
OpenVPN (TCP/UDP): Experiment with both TCP and UDP OpenVPN protocols in the ExpressVPN app. UDP is generally faster, but TCP might be more reliable in some CGNAT environments.
Lightway: While ExpressVPN's proprietary protocol, it may occasionally bypass CGNAT restrictions due to its design. Test its performance.
IKEv2: Less likely to bypass CGNAT, but worth a try as a process of elimination.
Port Forwarding (Limited):
ExpressVPN doesn't officially support port forwarding.
Some users report limited success by consistently connecting to the same VPN server location and hoping for static internal IP allocation. This is unreliable.
VPN Cascading (Double VPN):
Use ExpressVPN as a client behind another VPN provider that offers dedicated IPs or port forwarding.
This adds complexity and latency.
Alternative VPN Providers:
Consider switching to a VPN provider that explicitly offers dedicated public IPs as an add-on service. Examples include Mullvad, NordVPN (dedicated IP option), or AirVPN.
IPv6 (If Available):
If your ISP provides IPv6 connectivity, ensure it's enabled on your router and devices.
IPv6 bypasses NAT, potentially resolving connectivity issues. Verify IPv6 is working correctly through online test sites.
Install OpenVPN client: opkg update && opkg install openvpn-openssl
Download ExpressVPN OpenVPN configuration files: Obtain .ovpn files from the ExpressVPN website (requires login).
Configure OpenVPN:
Copy the .ovpn file to /etc/openvpn/.
Edit the .ovpn file:
Add your ExpressVPN username and password in a separate file (e.g., /etc/openvpn/auth.txt).
Update the .ovpn file to reference the auth file: auth-user-pass /etc/openvpn/auth.txt
Enable and start the OpenVPN service: /etc/init.d/openvpn enable && /etc/init.d/openvpn start
Firewall Rules (nftables example):
nft add rule inet filter FORWARD iifname "br-lan" oifname "tun0" ct state new,established counter accept
nft add rule inet filter FORWARD iifname "tun0" oifname "br-lan" ct state established,related counter accept
nft add rule inet filter OUTPUT oifname "tun0" ct state new,established counter accept
(Replace br-lan with your LAN interface and tun0 with your OpenVPN interface name)
DNS Leaks: Ensure you're using ExpressVPN's DNS servers or a trusted alternative (e.g., Cloudflare, Quad9) to prevent leaks.
IP Address Verification: Confirm your public IP address has changed after connecting to ExpressVPN.
Nordic Server Selection: Choose a server location physically located in a Nordic country (e.g., Sweden, Norway, Denmark, Finland, Iceland).
MTU Size: Experiment with different MTU (Maximum Transmission Unit) sizes on your router (e.g., 1400-1500) if you experience connectivity problems.
Test different ExpressVPN protocols.
Verify DNS leak protection.
Confirm IP address change.
Check IPv6 connectivity (if available).
Consider alternative VPN providers with dedicated IPs.