环境
国内，不翻墙状态,访问”http://connect.facebook.net/en_US/sdk.js”
日志
curl -v "http://connect.facebook.net/en_US/sdk.js"
#+begin_example
Hostname was NOT found in DNS cache
Trying 144.76.67.84…
Trying 2a01:4f8:191:8053::2…
Immediate connect fail for 2a01:4f8:191:8053::2: Network is unreachable
Connected to connect.facebook.net (144.76.67.84) port 80 (#0)
> GET /en_US/sdk.js HTTP/1.1 > User-Agent: curl/7.35.0 > Host: connect.facebook.net > Accept: / > < HTTP/1.1 301 Moved Permanently
Server nginx/1.8.0 is not blacklisted
< Server: nginx/1.8.0 < Date: Sun, 26 Apr 2015 08:36:22 GMT < Content-Type: text/html < Content-Length: 184 < Location: http://wpkg.org/my.js < Expires: Thu, 31 Dec 2037 23:55:55 GMT < Cache-Control: max-age=315360000 < X-Varnish: 366440577 360457 < Age: 88975 < Via: 1.1 varnish-v4 < Connection: keep-alive < <html> <head><title>301 Moved Permanently</title></head> <body bgcolor=”white”> <center><h1>301 Moved Permanently</h1></center> <hr><center>nginx/1.8.0</center> </body> </html>
Connection #0 to host connect.facebook.net left intact
#+end_example