(in other words: DNS problems/filters in Vietnam)
Vietnam hasn’t been blocking websites (like it’s neighbor China), but lately many people have had trouble connecting at least Facebook (both Viettel and FPT customers), so looks like there is some “experiments” with filtering going on.
Anyway, at least the problem with my Internet service provider (Viettel) is based on DNS server (DNS translates hostnames such as www.facebook.com to IP address such as 18.104.22.168), and it is easy to get around: Just change DNS server to some free public one.
I used 22.214.171.124 and 126.96.36.199 from OpenDNS, and everything seems to work again. Here are the instructions for changing DNS in Windows XP and here in Windows Vista. You need only change the “IPv4 IP” address.
Update: Now I cannot access the Facebook using OpenDNS server either. Also found this government order circulating in Internet, which is the ban for Facebook and some other sites. I’m not sure is that authentic or not, but it sure does look like authentic. The font and the style, etc., matches very well. At least very good fake if it’s not real.
Update 2: Using proxy helped this time. There are many proxy servers but I did a script which uses proxy only for the Facebook access. Instructions here.