I just traveled to Saigon, Vietnam. After checking hotel, I logged onto Wifi and browsed to Facebook. It won’t load!
zlu@zlu-mba:~$ ping www.facebook.com ping: cannot resolve www.facebook.com: Unknown host
Hmm, that was strange. A quick google search shows that some ISPs block Facebook due to government regulation. But the fix is quit easy. All you need to do is to change your DNS server to Google DNS (184.108.40.206).
In OSX, open System Preferences -> Network -> DNS, add 220.127.116.11 to DNS servers (making sure it’s the first in the list).
zlu@zlu-mba:~$ ping www.facebook.com PING www.facebook.com (18.104.22.168): 56 data bytes 64 bytes from 22.214.171.124: icmp_seq=0 ttl=238 time=269.573 ms
Now you can browse Facebook again.