@knuthollund so to me it now looks like that #someone-out-there creates lots of IPv4 connections to http://status.hackerposse.com/url/17460's webserver. And that explains why the local user gets "connection failed" with Firefox so often with IPv4. I guess your webserver has separate connection limits for IPv4 and v6. #Someone-out-there (maybe the lot of mastodon instances) saturate…