Server access logs show Facebook externalhit bot (126.96.36.199 - 188.8.131.52) and Bingbot (184.108.40.206 - 220.127.116.11) are blocked with a 403.
18.104.22.168 - - [26/Apr/2014:09:24:45 -0700] "GET /example.html HTTP/1.1" 403 911 "-" "Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)"
22.214.171.124 - - [26/Apr/2014:10:11:37 -0700] "GET /public/example.jpg HTTP/1.1" 403 910 "-" "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)"
Hits from Facebook and Bingbot from other IP ranges are given access with a 200 OK.
I have nothing in my custom htaccess blocking either of these IP ranges or User Agents (tested with 3rd party tools.) My site is up and running and thousands of other requests are being fulfilled without issue. However, I do see some other unexplained 403s blocking random human visitors for no explained reason.
To the best of my knowledge, this has been occurring for about 12 hours.
I can only assume these IP ranges are being blocked somewhere at the server admin level. I have sent in a support ticket but have not received a reply.
This is very serious and will do significant damage to my site's indexing at Bing, as well as hurt traffic from Facebook.
Can I get an admin to look into this ASAP? Thanks.