@MarcoE I have the exact same issue and I'm rather surprised that this functionality seems to be missing!

@MarcoE Is this still what you have to use? Or was it ever added as a feature?

@MarcoE 

I too am looking for a similar solution., I need to see my web server/web site through my OpenVPN client but I am unable to resolve the web site name when the tunnel is connected. I can resolve sites in the WWAN like Bing and Google but not my intranet site. When I use nslookup, I get a DNS server timeout error after 2 seconds from the gateway IP. I subscribed and set up DDNS with a TP-Link approved provider which I am still configuring. When I trace route and ping the servers, that works fine. The issue is whether there is a DNS server on the ER605 router that works as it should. I am using a Windows server system for DNS/DHCP which I have configured on the ER605 under advanced settings that works fine as long as I am not on the VPN. Does anyone know if there is a DNS server on this router? If not, is there a way to allow the VPN tunnel to see the Windows DNS server?

@jkexbx yes still after nearly one year the same silly situation. The products work very stable but useful features? Forget it.

@MarcoE 

It is starting look like I will need to revert my network back to pre-TP-Link standards as my previous Netgear router did have a good DNS server on it and the ability to set up an OpenVPN server (I think) on it. I had struggled with it trying to get it set up correctly but maybe I need to go back to it and try again. The idea of a enterprise level router not having a viable DNS server on it to support VPN tunnels is just beyond the pale. I am just upset that I spent a lot of my IT budget purchasing TP-Link hardware in the last couple of months only to have the main component turn out to be a bust over one simple thing, lack of a DNS server. I like the the Omada control system and the SDN EAP I bought. I just purchased a SDN capable switch but I have yet o open the box due to this issue with the ER605. If I end up reverting back to my original system configuration over this issue of the on board DNS server, I will send the switch back unopened as I already have two other switches I can use with my previous router. Such a shame that a company like TP-Link, with such a large market share, could fail so badly over this one piece that almost every other company can provide with little to no issue. Does anyone know if TP-Link has a different model router that is SDN capable with better DNS capabilities? I would also need OpenVPN access server capabilities.

Just pinging on this thread in case any progress has been made here (unlikely as it seems).

@ThomG 

All is good now. I fixed my network issues by utilizing the tech support pages and tweaking what they wrote against my system and managed to get it all to start working like it's supposed. It was a long endeavor but I learned a lot about TP-Link network products in the process. The answer was for me to use the built in DHCP server in the controller system for each new subnet I had configured rather than trying to get the router to route across the different subnets. Once I set that up for each leg, I applied the port configurations to the switches and everything is green and going. Thank you for asking.

@todonal glad to hear it, though I'm mostly interested in the internal DNS resolution without the controller. I see no evidence that support for this has been added to the firmware, but the thread is also a bit old, so maybe I missed something.

@todonal can you tell us exactly what settings you have done to get internal network names resolved? For me it is still not working and the support is definitely not helpful at all.

Kind Regards
Marco