Check FB debuger https://developers.facebook.com/tools/debug/og/object?q=hostname.sk- check HTTP response code of your webserver in access log – should be HTTP/1.1 200 OK (Facebook goes to IPv6 address by default)
tail -f /var/log/nginx/access.log 2a03:2880:2110:9ff4:: - - [20/Feb/2014:01:06:08 +0100] "GET /index.php HTTP/1.1" 301 0 "-" "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)" - Pokračovať v čítaní