Hi,

I'm using Network Manager and its OpenVPN plugin to configure a VPN 
connection. I can connect to the VPN, my IPv4 changes alright to an IP 
in a different Country, but my IPv6 doesn't change. According to the VPN 
provider, this is an IPv6 leak that makes it possible for services on 
the Internet to identify me. They say the best way to avoid that is to 
use their official app (which is not in available in Guix); but they 
also say one can disable IPv6 at the system level 
(https://protonvpn.com/support/disable-ipv6-protocol-linux/). I tried 
the latter in Guix System by modifying the sysctl service as follows in 
the OS config:

(modify-services
      %desktop-services
      ;; Enable Network Manager OpenVPN plugin.
      (network-manager-service-type
       config =>
       (network-manager-configuration
        (inherit config)
        (vpn-plugins (list network-manager-openvpn))))
      ;; Disable IPv6 to avoid IP leak when connecting to VPN.
      (sysctl-service-type
       config =>
       (sysctl-configuration
        (settings
         (append
          '(("net.ipv6.conf.all.disable_ipv6" . "1")
            ("net.ipv6.conf.default.disable_ipv6" . "1")
            ("net.ipv6.conf.lo.disable_ipv6" . "1")
            ("net.ipv6.conf.tun0.disable_ipv6" . "1"))
          %default-sysctl-settings)))))

However, https://ip.me/ still shows where I am by using IPv6.

I also tried disabling IPv6 from the GNOME settings for the configured 
VPN, but that doesn't seem to work either.

So, I'd really appreciate if anyone can share a functional configuration 
to prevent this kind of leak.

Thanks in advance,

-- 
Luis Felipe López Acevedo
https://luis-felipe.gitlab.io/