[ NoAccessorMethod ]
[ Version ( since = "1.52" ) ]
public int dhcp_ipv6_only_preferred { get; set; }
Controls the "IPv6-Only Preferred" DHCPv4 option (option 108 - RFC 8925).
When set to nm_setting_ip4_dhcp_ipv6_only_preferred_yes, the host adds the option to the parameter request list; if the DHCP server sends the option back, the host stops the DHCP client for the time interval specified in the option.
Enable this feature if the host supports an IPv6-only mode, i.e. either all applications are IPv6-only capable or there is a form of CLAT (464XLAT) deployed.
If set to nm_setting_ip4_dhcp_ipv6_only_preferred_auto, the option is automatically turned on when the IPv6 method is "auto" and the connection profile has ipv4.clat set to "yes" or "auto". If these two conditions are met, the host can operate in IPv6-only mode and therefore it is safe to disable DHCPv4 when the network also supports it.
When set to nm_setting_ip4_dhcp_ipv6_only_preferred_default, the actual value is looked up in the global configuration; if not specified, it defaults to nm_setting_ip4_dhcp_ipv6_only_preferred_auto.
If the connection has IPv6 method set to "disabled", this property does not have effect and the "IPv6-Only Preferred" option is always disabled.