Internet access does not working after connecting to Azure P2S VPN

Question

Internet access does not working after connecting to Azure P2S VPN

Ankit Badani 6

I have Virtual Network Gateway deployed in Sub1 with VNet of 10.12.0.0/16 and Gateway subnet of 10.12.255.0/27. VNet 10.12.0.0/16 has custom DNS Servers of 10.11.11.14 and 10.11.11.15, which are in another VNet of 10.11.0.0/16 with Sub2. While configuring Point-to-Site configuration, I am also advertising 10.11.0.0/16 subnet as an additional route. I can connect to Azure P2S VPN and can RDP into all the VMs that are running in 10.12.0.0/16. However, as soon as I connect Azure VPN Client, I cannot connect to Internet. My understanding is that only advertised routes will be routed over the Azure P2S tunnel. If I do a route print, I can see the 0.0.0.0/0 default gateway pointed to my home router. But I cannot do a nslookup or ping to outside world. I have tried disabling the firewall on the machine and also unchecked "Use default gateway on remote subnet" for the VPN NIC.

2 answers

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Answer 1

Jackson Martins 10,606 MVP Volunteer Moderator

Hi @Ankit Badani
Make sure there is no overlap ip with your local network.
You can try disabele forced tunneling, using Azure CLI like:

$gw = Get-AzVirtualNetworkGateway -Name <name of gateway> -ResourceGroupName <name of resource group>
Set-AzVirtualNetworkGateway -VirtualNetworkGateway $gw -CustomRoute @0

Reference : https://learn.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-p2s-advertise-custom-routes#forced-tunneling

Another way to add the new route on the client vpn is by accessing the routes configuration file. The file is at:

%appdata%\Microsoft\Network\Connections\Cm

You can open file called "routes"

and see all routes that are applied

You can remove or add routes in windows format, maybe remove the dafault gateway from VPN

Get in touch if you need more help with this issue.

--please don't forget to Accept as answer if the reply is helpful--

risolis 8,741 Reputation points

2022-06-05T04:41:06.933+00:00

Try to modify the XML file(VPN Client file) and start playing around if you want force tunneling or split tunneling....
Jackson Martins 10,606 Reputation points MVP Volunteer Moderator

2022-06-06T13:21:18.323+00:00

Just checking if there's any progress or updates?
younes zakiddine 0 Reputation points

2023-04-02T10:54:27.5266667+00:00

thanks for the details provided , where i can find the file called ' routes ' on macos

also to enable internet when using VPN i add 0.0.0.0 route right ?

Answer 2

Hi Guys,

I've tested this issue.

Steps performed:

New Azure VPN config downloaded from the Azure Portal VPN Gateway P2S (doesn't work)
Checking of ipconfig /all , route print, tracert, nslookup, test-netconnection, telnet, wifi/wired interfaces settings (all checked, no issues)
The problem is somehow related to the the Microsoft EDGE web browser DNS settings. When open Microsoft EDGE -> Settings -> search for "dns" -> look for "Use secure DNS to specify how to lookup the network address for websites". By default there is a settings set "Use current service provider". To solve the case and have the internet connection while on Azure VPN select "Choose a service provider", click in the empty field below and select e.g. "Cloudflare (1.1.1.1)". It will appear as "https://chrome.cloudflare-dns.com/dns-query". Screens attached. Then reboot the web browser - Microsoft Edge - and the internet will start to work right away.

20241105 edge dns1

20241105 edge dns2

Security info: In this Cloudflare DNS is used to resolve your DNS queries. If you do not want to do that try with your own DNS servers or other DNS you prefer in this step.

NOTE: If this will help you feel free to leave short comment or just share this to other that have such issue.

In case of questions feel free to let me know via comments as well.

Best regards,

Tomasz Wieczorkowski

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Internet access does not working after connecting to Azure P2S VPN

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