Strange DNS issue: DNS resolution failed for *****

Viscosity Support (Windows)
1

Since last week I cannot connect to my VPN server from Windows. Viscosity log directly reports: DNS resolution failed for *****

I checked the the folowing:

  • Checked the DNS addres: Windows does resolve the addres, it is reachable by ping;
  • Check the VPN connection on another, Linux, machine using OpenVPN. No problem;
  • Updated and reinstalled Viscsocity to version 1.12.1;
  • I’m using Windows 11, 24h2, updated to the june security patch (KB5094126);
  • Rebooted Windows (of course :-D).

Prior to this issue I did not make any modifications to either Windows or Viscosity.

Is there something else I could do to fix this?

2

Hi Buddy6296,

Assuming it’s resolving in the command prompt fine, then it’s generally it’s one of two things:

  1. The IP version your VPN connection is set to use. The address may only be resolving to IPv4 or IPv6, but your VPN connection is configured to use the other version. You can check by editing your connection in Viscosity, and checking what the “Protocol” drop down menu is set to (e.g. UDP vs UDPv4 vs UDPv6).

  2. Endpoint security software is filtering or blocking the DNS resolution. Check for any such software installed (antivirus, firewall, network security, filtering software, etc.) and make sure it’s not blocking or filtering Viscosity.

Cheers,
James