topic Re: Prevent 3rd party VPN from changing DNS in General Topics

Prevent 3rd party VPN from changing DNS

fhewiufhwefhwe — Mon, 17 May 2021 18:36:31 GMT

I am connecting to a 3rd party vpn, also a palo alto. How can I prevent the 3rd party vpn from changing the dns servers that I use?

Re: Prevent 3rd party VPN from changing DNS

aleksandar.astardzhiev — Tue, 18 May 2021 08:51:26 GMT

Hi @fhewiufhwefhwe ,

If you have admin access to the computer you are connecting you can delete the DNS settings configured on the GlobalProtect interface once you connect.

After all GlobalProtect is just creating another standard interface, only difference between the GP interface and your physical interface is that GP will use higher priority/metric to ensure any route pointing to the tunnel will take presedence. This priority will affect the DNS server order in which your PC will try to use.

The problem with this approach is that you need to do it every time you connect to the VPN. Probably you can script this and just run the script once you connect.

The better approach would be to discuss with VPN administrator and ask them if they can create a separate client config for your that does not assign DNS settings.

Re: Prevent 3rd party VPN from changing DNS

Mick_Ball — Tue, 18 May 2021 09:37:36 GMT

I'm not so sure that will work as it will still try to send via tunnel... you will need a custom gateway config with your required network services and also either split tunnel or access to local network depending on your DNS server location.

Re: Prevent 3rd party VPN from changing DNS

OtakarKlier — Wed, 19 May 2021 19:56:53 GMT

Hello,

I'm wondering if you manually set them and leave the IP, Subnet mask, and gateway on dhcp if that will work? I would recommend using a secure DNS provider (either Palo Alto's) or on of the others, some are free. This way its another layer you are protected at.

Regards,

Re: Prevent 3rd party VPN from changing DNS

fhewiufhwefhwe — Wed, 19 May 2021 20:07:45 GMT

I have ipaddress reservations for the machine, and am using a secure DNS. It's the 3rd party VPN that is overriding the dns. The VPN simply exposes an application, change the machine dns based on nslookup, and are not RDPing into another machine.