Facebook Scraped URL 404 and welcome to Nginx error [Ningx + PHP-FPM]

Question

Simply my problem is: When I share my site url on Facebook it shows a "404 Not Found" title or "Welcome to Ningx" Title.

I am new to Ningx, I am using Debain Linux (Ningx + PHP-FPM) Config. All sites hosted on this server having a problem wile Scrape Information by Facebook (Open Graph)

https://developers.facebook.com/tools/debug/og/object?q=http%3A%2F%2Fopenspeedtest.com%2F

og:url  http://openspeedtest.com/
og:type website
og:title    Welcome to nginx!
og:updated_time 1400314069

404 Note Found Example ----> https://www.facebook.com/sharer/sharer.php?u=http%3A%2F%2Fshar.es%2FV1oDa&t=Internet+Speed+Test+for+Any+Device%2C+Any+Broadband+-+OpenSpeedTest.com Welcome to Ningx Example ---> https://www.facebook.com/sharer/sharer.php?u=http%3A%2F%2Fshar.es%2FV1WWn&t=Check+out+my+Internet+SpeedTest+results.+What%27s+your+speed%3F

I have not write "og" tags for my Old Website eg: https://developers.facebook.com/tools/debug/og/object?q=http%3A%2F%2Fcheckinternetspeed.in%2F Also Getting Same Error with my server.

I tested the different Ningx config to solve this problem but failed. Google+ is taking correct title and images from my server.

Answer 1

I wasted 5+ Hours on google for this issue, finally I got assistance from my hosting provider. This problem occurs due to IPV6 address. Facebook by default use IPV6 address if available. My VPS has IPV6 enabled.

To Solve this problem you have to enable iPv6 in All Ningx config files for each virtual host (if many sites hosted) to listen Any IPv6 address at port 80.

This will solve the issue with Facebook opengraph.

Alternatively, you can completely disable IPV6 address to solve this issue.