VPN router behind ISP router

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New Around Here

My setup is as follows:

ISP router -> various computers, zxytel t-50
VPN Router,->Smart TV, Asus N66U

I am trying to get a openvpn client running on the asus router, but I keeep geetin routing IP issues preventing connection.
I have gotten a GL.iNet running the openVPN client behind the t-50 so I know it's possible without changing t-50 settings.

Can someone give me a rundown of the proper Lan and Wan settings for the Asus to get it to play nice with the t-50. I would continue with the GL.iNet but it doesn't have the clock speed for the 4k TV I so cleverly upgraded to. I am aware the N66U might not either but I want to check before I go and by something new.


Part of the Furniture
The firmware you're running and the ISP speeds you're paying for are also important to note here.

The easiest way for you to test is to plug in the RT-N66U to your ISP's router and test it there.

Otherwise, you will have to forward ports on the Zyxel T-50 to allow the double NAT'd RT-N66U to 'see' the internet.


Part of the Furniture
You need to double NAT your VPN router behind your ISP router. It will work fine.


  • How to double NAT two routers.txt
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New Around Here
Double NAT worked well. Unfortunately, N66U isn't fast enough so I went and bought an AX55. Hopefully this will be enough. Thanks much!


Part of the Furniture
Yes the N66 does top out at about 20 Mbps for a VPN client. I don't know what processor speed the AX55 has but with a faster processor you can expect about 60 Mbps. For even faster speeds you need a processor that supports AES-NI then speeds over 200 Mbps are possible when using a client on a router.

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