Re: NM VPN does not allow IPv6-only connections?

[Tore Anderson <tore fud no>]

* Joel Goguen via networkmanager-list

> When connecting to a VPN using NetworkManager (specifically tried using
> OpenConnect but the bug looks to be in the NetworkManager core code) with IPv4
> disabled, connecting fails. NetworkManager attempts to get an IPv4 configuration
> anyway and fails if it isn't present.
>
> On one VPN, with IPv4 disabled and no IPv4 DHCP in use, connecting failed
> because no IPv4 config could be found. With the same VPN profile, IPv4 disabled,
> but IPv4 addresses being handed out via DHCP, NetworkManager still looks for a
> connection and configures IPv4 even though it's disabled.
I can confirm this bug on Fedora 29. If I set ipv4.method=disabled on an OpenVPN
connection profile (where the server offers both IPv4 and IPv6 addressing), NM
will ignore that and configure IPv4 anyway:

$ nmcli con show myvpn | egrep '^ipv4|IP4'
ipv4.method:                            disabled
ipv4.dns:                               --
ipv4.dns-search:                        --
ipv4.dns-options:                       ""
ipv4.dns-priority:                      0
ipv4.addresses:                         --
ipv4.gateway:                           --
ipv4.routes:                            --
ipv4.route-metric:                      -1
ipv4.route-table:                       0 (unspec)
ipv4.ignore-auto-routes:                no
ipv4.ignore-auto-dns:                   no
ipv4.dhcp-client-id:                    --
ipv4.dhcp-timeout:                      0 (default)
ipv4.dhcp-send-hostname:                yes
ipv4.dhcp-hostname:                     --
ipv4.dhcp-fqdn:                         --
ipv4.never-default:                     no
ipv4.may-fail:                          yes
ipv4.dad-timeout:                       -1 (default)
IP4.ADDRESS[1]:                         10.66.1.6/32
IP4.GATEWAY:                            10.66.1.5
IP4.ROUTE[1]:                           dst = 10.66.1.1/32, nh = 10.66.1.5, mt = 50
IP4.ROUTE[2]:                           dst = 0.0.0.0/0, nh = 10.66.1.5, mt = 50
IP4.ROUTE[3]:                           dst = 10.66.1.5/32, nh = 0.0.0.0, mt = 50
IP4.DNS[1]:                             <snip>
IP4.DOMAIN[1]:                          <snip>

Tore