Share via

Connecting to VPN server failed with exception : no such host is known

abc 16 Reputation points
2020-08-06T10:57:27.093+00:00

I am trying to setup P2S VPN with AAD authentication following the document.

https://zcusa.951200.xyz/en-us/azure/vpn-gateway/openvpn-azure-ad-tenant

After setting up the Virtual network gateway I downloaded the vnp client and imported the azurevpnconfig.xml to the azure vpn client app. But the azure vpn client fails to establish connection once clicked on connect button . the connection fails with "No such host known" . Wanted to understand if i am missing anything in the configuration ? Need help

Azure VPN Gateway
Azure VPN Gateway
An Azure service that enables the connection of on-premises networks to Azure through site-to-site virtual private networks.
1,543 questions
0 comments

4 answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Gilmar Junior 21 Reputation points
    2022-01-28T13:13:49.493+00:00

    Hi guys... (It applies only to Windows 10...on Windows 11, Azure VPN Client + Umbrella Roaming Client works just fine)

    The following workaround works... in order to use the Azure VPN Client on Windows 10.

    Add an entry in the Windows Hosts file... " IP + Azure URL".

    Doing that, we were able to connect to Azure via app Azure VPN Client.

    Hope it helps you guys as well.

    A collegue of mind figured it out. Tks Alexandre!

    Cheers!

    4 people found this answer helpful.
  2. GitaraniSharma-MSFT 49,616 Reputation points Microsoft Employee
    2020-08-06T11:56:46.98+00:00

    Hello @abc ,

    "No such host is known" is a very common Windows error that happens when the OS is unable to determine the IP address to connect to. This is usually due to failing DNS resolution.

    So, to start the troubleshooting, I would request you to run the Diagnose tool as mentioned in the below article and see if there are any errors:
    https://zcusa.951200.xyz/en-us/azure/vpn-gateway/openvpn-azure-ad-client#diagnose

    Post this, you can try to clear the DNS client cache with ipconfig /flushdns and reboot your machine.

    Another known cause for this issue is related to Cisco Umbrella roaming client. If you are using this Cisco Umbrella client then that is the issue. Please refer below articles for more information:
    https://support.umbrella.com/hc/en-us/articles/230561147-Umbrella-Roaming-Client-Compatibility-Guide-for-Software-and-VPNs
    https://support.umbrella.com/hc/en-us/articles/115004651446-Windows-10-Native-VPN-API-Modern-Metro-apps-

    Kindly let us know if the above helps or you need further assistance on this issue.

    ----------------------------------------------------------------------------------------------------------------

    Please don’t forget to "Accept the answer" wherever the information provided helps you, this can be beneficial to other community members.

    1 person found this answer helpful.
  3. Derek Gabriel 11 Reputation points
    2020-08-12T21:22:40.287+00:00

    I'm experiencing the same situation when I run diagnostics, all the test pass. The only error I can find anywhere in the logs is:

    [Error] Connecting to VPN server failed with exception: No such host is known.

    However, on the line above that is the VPN Server name azuregateway-xxxxxxxxxxxx..vpn.azure.com and I can resolve that at command prompt.

    Should there be any other DNS settings that we need to modify on the client?

  4. Mike Crowley 206 Reputation points
    2022-09-14T21:34:48.277+00:00

    An important detail here is that while the VPN client is established, the name routing policy may have an entry sending all DNS traffic over the tunnel, whereas when the VPN is disconnected, the queries go to the client's local provider.

    you can see the policy via: Get-DnsClientNrptPolicy on the client.

    0 comments

Your answer

Answers can be marked as Accepted Answers by the question author, which helps users to know the answer solved the author's problem.