Here is a tutorial on how to connect a DD-WRT router to NordVPN servers via the OpenVPN GUI client:
It has been made using this configuration:
Firmware: DD-WRT v3.0-r27520M (07/17/15) kong
Hardware: Netgear WNR3500L v2
1. In the DD-WRT Administrative Interface, navigate to Setup > Basic Setup. Under Network Address Server Settings (DHCP), set these NordVPN DNS addresses:
Static DNS 1 = 22.214.171.124
Static DNS 2 = 126.96.36.199
Static DNS 3 = 0.0.0.0 (default)
Use DNSMasq for DHCP = Checked
Use DNSMasq for DNS = Checked
DHCP-Authoritative = Checked
Then, Save and Apply settings.
If you’re setting up two routers, you should change the second router Local IP address to be different than the main router’s. (In this case main router’s IP is 192.168.1.1, while the one we’re connecting to NordVPN server is accessible via 192.168.2.1)
2. Navigate to Setup > IPV6. Set IPv6 to Disable, then Save & Apply Settings.
(this is a recommended step to make sure you get no IP leaks)
3. Navigate to Service > VPN. Under OpenVPN Client, set Start OpenVPN Client = Enable, to see the options necessary for this configuration. Then set the following:
Server IP/Name = For the sake of the tutorial, we have used us936.nordvpn.com, but you should connect to a server suggested to you at https://nordvpn.com/servers/tools/ . You can find the server hostname right under the server title.
Port = 1194
Tunnel Device = TUN
Tunnel Protocol = UDP
Encryption Cipher = AES-256-CBC
Hash Algorithm = SHA-512 (note: older NordVPN servers use SHA-1 instead. If SHA-512 does not work, select SHA-1)
User Pass Authentication = Enable
Username, Password = Your NordVPN credentials
Note: If the Username and Password fields are missing, fill in the remaining fields and proceed to step 3.1
Advanced Options = Enable (this will enable additional options)
TLS Cipher = None
LZO Compression = Yes
NAT = Enable
The options not mentioned in this guide should be kept with default values.
3.1. (Optional, depending on step 3.) If the Username and Password fields are missing, go to Administration > Commands, and enter this code:
echo "YOURUSERNAME YOURPASSWORD" > /tmp/openvpncl/user.conf /usr/bin/killall openvpn /usr/sbin/openvpn --config /tmp/openvpncl/openvpn.conf --route-up /tmp/openvpncl/route-up.sh --down-pre /tmp/openvpncl/route-down.sh --daemon
Replace YOURUSERNAME and YOURPASSWORD with your respective NordVPN account credentials. Click Save Startup, and return to the previous VPN tab.
4. In Additional Config box either enter or copy/paste these commands:
remote-cert-tls server remote-random nobind tun-mtu 1500 tun-mtu-extra 32 mssfix 1450 persist-key persist-tun ping-timer-rem reneg-sec 0 #log /tmp/vpn.log #Delete `#` in the line below if your router does not have credentials fields and you followed the 3.1 step: #auth-user-pass /tmp/openvpncl/user.conf
5. Download the CA and TLS certificates here.
You should then unzip it using your extractor (WinRar, 7-zip, etc.) so you see the servers folder.
6. In the folder, open the CA.crt file of the server you chose to use (in our case, us936_nordvpn_com_ca.crt) with a text editor, such as Notepad.
7. Copy its contents into the CA Cert field. Be sure the entire text gets pasted in, including
-----BEGIN CERTIFICATE----- and
-----END CERTIFICATE----- lines.
8. Open the TLS.key file of the server you chose to use (in our case, us936_nordvpn_com_tls.key) with a text editor, such as Notepad.
9. Copy its contents into the TLS Auth Key field. Be sure the entire text gets pasted in, including
-----BEGIN OpenVPN Static key V1----- and
-----END OpenVPN Static key V1----- lines.
10. After entering all this data, Save and Apply Settings.
11. To Verify the VPN is Working, Navigate to Status > OpenVPN
Under State, you should see the message:
Client: CONNECTED SUCCESS.
12. To create a kill-switch, you can go into Administration > Commands, and enter this script:
WAN_IF=`nvram get wan_iface` iptables -I FORWARD -i br0 -o $WAN_IF -j REJECT --reject-with icmp-host-prohibited iptables -I FORWARD -i br0 -p tcp -o $WAN_IF -j REJECT --reject-with tcp-reset iptables -I FORWARD -i br0 -p udp -o $WAN_IF -j REJECT --reject-with udp-reset
Then select Save Firewall, Go into Administration > Management > Reboot router.