ANSWERED Ubuntu 20.04 AirVPN using openvpn3 DNS Leak

[UserAccount 1]

Hello,

Novice here in the early stages of learning about linux and networking.

I have a computer running Ubuntu 20.04 that is being used as a router. Modem is plugged into the WAN port and a wifi-router running DD-WRT configured as a WAP is plugged into the LAN port.

I connect to AirVPN using openvpn3 as described on this site: https://community.openvpn.net/openvpn/wiki/OpenVPN3Linux?__cf_chl_jschl_tk__=50aa898758c01ce877a8fb138826a2b8c24723df-1603064387-0-AUXS0W3rOsW1kgOEbLz7kiQykgXgtOfuhYTl9roRJPWcs0A6syIfkG-5ugYbOUFLQU_MrXyLMcBSD3dUmIGFMHMjF2KlIGULaHVZStJuG61d7jSAORhsTy4ifRU_m2rp1djwh4HefwnCUPg9AgHLwgi7qy-WAyKdKi9QO_uyZrbgZegpo95tDnUtL4uziBW7TBvREtfyHCA1GPZlp9HPMiQ_PGXRVdpSBkFZqRhx6e36yi9jn1zkJQhPbN1ky6vSicix2mCFQhbOTirPbW0KNsWojjC94K_nOMXe4sCIrxWMZ0tKWWvcyhA3_GQv4pyW0w

Works great!

When checking public IP and DNS on the Ubuntu machine, they are the same (IP of the AirVPN server in use)

However, when checking public IP and DNS on any device connected via wifi, result is public IP of AirVPN server and DNS is of a cloudflare server.

Let me know what further information would be helpful, such as iptables or my network interface configuration.

Any advice will be appreciated, thank you!

[OpenSourcerer 1435]

So.. what do you need help with?

No, really, be a bit more precise on what you want to achieve. Right now you gave some facts and an observation that seemingly is unexpected, but what you want to achieve turns into a guessing game. So I'm guessing you want to use AirDNS and not Cloudflare on wireless devices.
To do so, you must set your wireless devices to use AirDNS, either manually or via DHCP. On Android, this should be easy as every wireless connection can have its own network settings, and so you can set the DNS server to be AirDNS for the connection to that router. Same on iOS, I believe. Should you connect with a Linux computer, you can even set multiple profiles with different settings for one connection.
The DHCP thingy is more complicated unless you want all devices in your network without exceptions to use the VPN and AirDNS, in which case you can simply set the DHCP server to push out the AirDNS addresses. Then reconnect all devices. The advantage is that it will also cause Windows to use it without reconfiguring its network settings every time you leave the house or come back (because the manual DNS server setting remains in effect across connections).

Also, on Android, disable DNS-over-HTTPS, sometimes called "secure DNS" or "encrypted DNS" in Android settings > Wireless/Connections. Sometimes it's in the Advanced section there, really depends on the UI you're using, sometimes it's part of the per-connection network settings. In any case, this being enabled will effectively prevent using AirDNS.

[UserAccount 1]

9 hours ago, giganerd said:

So.. what do you need help with?

No, really, be a bit more precise on what you want to achieve. Right now you gave some facts and an observation that seemingly is unexpected, but what you want to achieve turns into a guessing game. So I'm guessing you want to use AirDNS and not Cloudflare on wireless devices.
To do so, you must set your wireless devices to use AirDNS, either manually or via DHCP. On Android, this should be easy as every wireless connection can have its own network settings, and so you can set the DNS server to be AirDNS for the connection to that router. Same on iOS, I believe. Should you connect with a Linux computer, you can even set multiple profiles with different settings for one connection.
The DHCP thingy is more complicated unless you want all devices in your network without exceptions to use the VPN and AirDNS, in which case you can simply set the DHCP server to push out the AirDNS addresses. Then reconnect all devices. The advantage is that it will also cause Windows to use it without reconfiguring its network settings every time you leave the house or come back (because the manual DNS server setting remains in effect across connections).

Also, on Android, disable DNS-over-HTTPS, sometimes called "secure DNS" or "encrypted DNS" in Android settings > Wireless/Connections. Sometimes it's in the Advanced section there, really depends on the UI you're using, sometimes it's part of the per-connection network settings. In any case, this being enabled will effectively prevent using AirDNS.

I apologize for the lack of precision

I want all devices in my network without exceptions to use the VPN and AirDNS, this is where I seem to be missing something.

Your reply is very helpful, it seems the problem is that I had option domain-name-servers 1.1.1.1, 1.0.0.1 specified in my dhcpd.conf file.

I changed these to 192.168.1.1, 192.168.1.2 and now the wifi devices are also using AirDNS along with my Ubuntu machine.

Cheers!

  Edited ... by UserAccount
solved