SFT1200 VPN DNS issue on the v4.7.2

Technical Support for Routers
1

I did an upgrade to 4.7.2 over the weekend on an SFT1200.

The upgrade worked OK, but I found DNS stopped working, so I reloaded the current release and restored from backup.

I have an always on Wireguard connection and while the routing was fine, checked using traceroute for a target IP address, DNS would not resolve.

The only clue I found was that there was an extra entry for the DNS servers which was populated with the SFT1200's LAN IP address. I tried various DNS server configurations but was unable to get to one where DNS worked. Hence the roll-back.

2

Hi,

Here creates the new thread for troubleshot this issue.

Is the VPN Client connection normal?
The VPN server is from a VPN service provider or a self-built server?

Is the ping <IP> normal, and the ping <domain name> is abnormal?

Screenshot the GL GUI > Network > DNS to check.

4

The VPN connection is configured in what is normally considered to be a Road Warrior configuration.

All aspects of the configuration looked to be running normally apart from the DNS. But that's not to say I tested the functionality of all aspects of the router. I just focused on the DNS issue.

I don't use any public VPN services. All the Wireguard services are running on OPNsense firewalls that I have full control of. The far-end for this one being in the USA. The VPN servers have been running for about 5 years and there were no DNS issues with 4.3.21 prior to the upgrade or after 4.3.21 had been re-installed.

When running traceroute (mtr) to an <IP> address timings were as expected.

ping <domain name> did not work because DNS would not resolve.

Additionally when watching the far-end firewall logs, DNS requests from the router were not seen.

I'll try and do this when I'm back from Europe, around the end of next week.

5

Is this profile of SFT1200 available when imported and used on the WireGuard client on your computer?

This issue has not been reproduced yet. If it does not work, we may ask you provide a remote desktop to check for the issue.

6

I'll try and do a clean install of 4.7.2 and re-test over the weekend.
I might not manage this as I'm currently preparing to be in the US next week.

7

Also please test the profile on the computer WireGuard APP, to see if the VPN tunnel works.

No problem, please contact me at that time when you available to remote check.

8

The traceroute showed that the traffic was routed correctly over the VPN.

9

I'm not seeing this issue with a OpenVPN client on my Opal running 4.7.2

10

If available, please PM to share the VPN profile with me.

If not, please PM to share me the issue syslog.