ipv6 windows How to disable IPV6?

[MadeUpName12 0]

Hello people, new here, happy so far. 

Win 11 pro 25H2
OpenVPN 2.6.14
OpenVPN GUI 11.55.0.0

I used the config generator, that is really slick by the way, selected the specific servers I wanted, and set it to IPV4 only but, I'm still seeing IPV6 connections on the outside. 

Well, I was until I added these last 3 lines to the config. Now I just see errors (below) in the connection log telling me it's doing what I want but, why is it trying to make these connections at all? All the little IPV6 check boxes are unchecked everywhere on the LAN. 

Can I stop it from trying?

It makes the log popup and stay on the screen when I connect. Just a small annoyance but little errors bug me, especially when I have to respond to them every time, even with a single click.

WARNING: OpenVPN was configured to add an IPv6 route. However, no IPv6 has been configured for OpenVPN Data Channel Offload, therefore the route installation may fail or may not work as expected.
 

client
dev tun
remote 198.44.129.210 1194
resolv-retry infinite
nobind
persist-key
persist-tun
auth-nocache
verb 3
explicit-exit-notify 5
rcvbuf 262144
sndbuf 262144
remote-cert-tls server
data-ciphers AES-256-GCM:AES-192-GCM:AES-128-GCM
data-ciphers-fallback AES-256-GCM
proto udp
auth SHA512
block-outside-dns
auth-user-pass xxxxxxxxxxx
pull-filter ignore "ifconfig-ipv6"
pull-filter ignore "route-ipv6"
pull-filter ignore "tun-ipv6"

[Staff 10708]

@MadeUpName12

Hello!

There are two separate things in your configuration.

1. Please remove the line "auth-user-pass ...". AirVPN does not use a username and password for OpenVPN: the connection is authenticated by the certificate and the key that are already inside the file built by the Config Generator, and the Config Generator never adds auth-user-pass. With that line, OpenVPN asks for a username and a password, or reads them from the file you name there. If that file is missing or cannot be read, OpenVPN stops before it connects.

2. About IPv6. Our OpenVPN servers offer IPv6 inside the tunnel to every OpenVPN client. So with OpenVPN, the IPv4-only exit setting of the Config Generator is not enough by itself, and that is why you still saw IPv6 at the exit. The line that solves it is one of the lines you added:

pull-filter ignore "ifconfig-ipv6"

With WireGuard, instead, the IPv4-only exit setting of the Config Generator works as expected: the WireGuard file gets only an IPv4 address and routes only IPv4 into the tunnel. In that case IPv6 is not routed into the tunnel at all, so the same note below applies: keep IPv6 disabled on your network adapters.

The line with "route-ipv6" does no harm and can stay. The line with "tun-ipv6" can be removed: that option has no effect in OpenVPN 2.6.

The warning comes from another option that the server sends, "redirect-gateway ipv6". It routes all the IPv6 traffic of your computer into the tunnel, so that IPv6 can never go out outside the VPN. The tunnel now has no IPv6 address, so OpenVPN warns that the IPv6 routes may not work. This is exactly what you want: IPv6 has nowhere to go. The warning is harmless, and we suggest to keep the configuration as it is.

If you still want to remove the warning, you can replace that server option with an IPv4-only one, by adding these two lines:

pull-filter ignore "redirect-gateway"
redirect-gateway def1 bypass-dhcp

After this change IPv6 is no longer routed into the tunnel. Do it only while IPv6 is disabled on all your network adapters. If Windows gets IPv6 back (for example after an update, or on a new adapter), your IPv6 traffic would go out outside the VPN.

If the log window still stays open after these changes, please paste here the lines of the log from "Initialization Sequence Completed" on. If you paste the configuration again, remove the certificate and key blocks first.

Kind regards