For this tutorial we will assume that your router has already been flashed with DD-WRT firmware and that your router's IP address is set to 192.168.1.1. You also must be sure your router first has internet access and that your local network and ISP configuration allows PPTP or L2TP/IPsec.
Connect to the DDWRT router via ethernet cable or by logging in to the wireless network "dd-wrt". Open a new web browser and access the following address: http://192.168.1.1 (Please first set your network connection to "obtain the IP address automatically" if you connect via ethernet.
Next, go to Setup then select Basic Setup.
Here is a checklist of common causes and fixes.
1. Try setting 'Use DNSMasq for DNCP', 'Use DNSMasq for DNS' and 'DHCP-Authoritative' to enabled as well as disabled.
2. Ensure the IP of the DD-WRT router is not conflicting with your main router. If your main router is currently 192.168.1.1 DD-WRT has to be in the same subnet, an example of ithis is: 192.168.1.51
3. Ensure the DD-WRT is connected to any other router from its WAN port.
4. You could also try setting the DD-WRT router to a 'Static' connection from the 'Basic Setup' page.
5. Go to your LAN settings and manually change your IP Address, Subnet Mask and Gateway so its pointing to the DD-WRT router. You may also need to change the DNS servers, if you do not want to use your ISPs DNS you can use Google DNS 126.96.36.199 and 188.8.131.52
6. If you have setup a PPTP connection try adding: mppe required,no40,no56,stateless into the 'Additional PPTP Settings' text area.
7. If you have setup a PPTP connection please ensure the PPTP passthrough is enabled from Security -> VPN Passthrough.
8. Try disabling the firewalls on your routers or modems, these can quite often cause connection issues. Once its determined that a firewall is not causing the problem it can always be re-enabled.
9. MTU settings can quite often cause problems, you could try lowering the MTU settings by adding this command on a new line (below verb 3) on your OpenVPN configuration file: tun-mtu 1100
10. Its very important that your router has the correct time and date.
If you are running an OpenVPN Connection you can create a Log which may enable you to see the problem - so you can open a support ticket and send us the details.
1. Add the following after 'verb 3' in your OpenVPN Config startup script:
2. Reboot you router, wait for about 5 minutes and then run the following command (Run Command) from the command text area in administration (same place as the OpenVPN config file):
ln -s /tmp/openvpn.log /tmp/www/openvpnlog.html
3. Go to the DD-WRT index page and add: /user/openvpnlog.html to it so it looks something like: http://192.168.x.x/user/openvpnlog.html
## If any problems persist please open a support ticket and we will be able to assist you with Your troubleshooting.