Cannot connect to VPN using a DD-WRT router

[#1]

I have a Linksys 1900AC router with DD-WRT.

I have connected the LAN of my Hub One router to the WAN of the Linksys router.

I have configured the Linksys router according to the instructions and enormous help from my VPN.

The Linksys cannot connect to the VPN.

My VPN suggests there might be a problem with the Hub One router.

I had the same problem using another VPN.

I'm using OpenVPN on the DD-WRT router.

[#2]

How have you configured the Linksys as the first thing which come to me is "double NAT" caused by two routers connected back to back.  It adds an extra level of configuration.

The simplest fix is to get a modem only device, the Hub Two supplied by Plus Net works in bridge modem. The Hub One cannot be configured to bridge mode.

Some reading on Double Nat and More info

HTH

[#3]

Thanks Dan.

Following your first link, I eventually ended up replacing the Plusnet One router with an ASUS DSL-AC68U router/modem that I had to stop using with my VPN.

The aim was to turn it into a bridge, as you suggested, but I didn't need to. I used the DMZ setting in the ASUS to allow the DD-WRT router to access the internet.

I've sent logs and screenshots to my new VPN to check if the connection is secure. So many settings that I don't understand.

Anyway, it's working after a fashion.

[#4]

@andrewemondson  You don't sound too confident about the Asus if it's only working after a fashion.🤔

Just want to let you know that the Asus DSL-AC68U contains probably the worst ever VDSL2 modem chip and is well known to behave very badly on Openreach FTTC services. I doesn't get on well with the OR DLM (dynamic line management system) so don't be surprised if you find your line dropping out and your speed reducing and being capped at lower levels.☹️

Also if it not in Bridge mode you will still have the Double Nat situation.

[#5]

BT/Plusnet hubs have a default LAN IP of 192.168.1.254.

If the dd-wrt router is just running an openvpn client to connect to an external VPN service provider, the default LAN IP of ddwrt routers tends to be 192.168.1.1.   

Did you remember to change dd-wrt LAN IP, to say 192.168.2.1, to avoid ddwrt routing issues ?

[#6]

Thanks for the replies.

I'll see how the ASUS router performs before changing it.

Yes, I assigned it a different ip address.

[#7]

The ASUS DSL-AC68U router is working fine with OpenVPN, so I won't be returning to the Plusnet One.

I have finished my trial with NordVPN, which worked well; however, it is more expensive than my current VPN, who are unable to get the same setup working.

I'll make a post on the DD-WRT forum to see if anyone can solve the problem, in light of the NordVPN success.

If they cannot, I'll abandon the OpenVPN project and just stick to the VPN Windows client.

Thanks for your help.