It seems recently the OSM tile CDN has started answering over IPv6.

So perishes my quick check whether I’m connected via an IPv6-only network, where osm.org/ used to show a blank map on the rest of the homepage, and I know immediately a workaround is needed. Always was my second action after connecting to https://ipv6.google.com/intl/en/ipv6/statistics.html .

In other words, yay, now to give forum.osm the same connectivity, and a few external sites, then I can catch up with OSM without paying attention to how I’ve been connected.