MT2500A not always reestablishing DNS after VPN use

Technical Support for Routers
1

I first noticed this issue after connecting as a client using WireGuard to Private Internet Access (PIA) from an MT2500A using the latest 4.1.1 firmware, but I’ve had the same problem after connecting to a remote Flint server.

The problem materialises as follows:

  1. The internet is working fine when connected via the MT2500A wth DNS set to “Automatic”. The MT2500A uses my local DNS server (on 192.168.1.1)
  2. I connect to a remote WireGuard server (PIA or the private Flint server) and again everything is working fine. A different public DNS server is used for these connections.
  3. I disconnect the VPN service and I’m no longer able to resolve DNS queries despite the DNS page of the MT2500A showing that it is on Automatic, connected to 192.168.1.1.
  4. I change the DNS to “Manual” and choose a public server (OpenDNS). Everything starts working again.
  5. I change back to “Automatic” and the server switches to 192.168.1.1. Everything continues working.

I haven’t had this happen universally on every occasion but it seems like the firmware isn’t always resetting DNS correctly when a WireGuard tunnel is closed down.

Any comments?

2

I have tested with version 4.1.1 and there is no recurrence of this problem. Do you get the same result in multiple tests?

3

Thanks for your reply! I’ll do that and let you know.