WAN IPV6 gateway monitoring stops operating.

[mmcvey7355]

Observations.

If a router solicit and response sequence fully completes before the DHCP6 processes starts all will be fine.

If DHCP6 completes before the solicit / response happens and/but the DHCP6 advertisement does not contain router information in the response (assumption to follow) the processes to listen for RA's to operate GW monitor functions stop running.

My ISP only provides address, delegation, and DNS in the DHCP6 advertisement.

Fix/Workaround.
Be sure do not wait for RA is unchecked in WAN interface configuration.

This was not an issue in the 2.4 train, and the "Do not wait for RA" was beneficial to ensure prefix delegation for track interfaces was successful. (confirmed via a reinstall of 2.4.5-p1 and restore config.)

[jimp]

The last few comments on https://redmine.pfsense.org/issues/11454 should handle this, it was another simple fix.

https://github.com/pfsense/pfsense/commit/ec3fd7e5e43ac28def2ff0bcd36c9b741a7fab32