It's normal to Bitcoin Forum 
My trouble is:
What is 8.7.198.45? Is it Bitcoin Forum's IDC?
Code:
~$ ping -s 1 -c 1 bitcointalk.org
PING bitcointalk.org (107.21.115.227) 1(29) bytes of data.
--- bitcointalk.org ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms
PING bitcointalk.org (107.21.115.227) 1(29) bytes of data.
--- bitcointalk.org ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms
My trouble is:
Code:
~$ nslookup bitcointalk.org
;; Got SERVFAIL reply from xxx.xxx.xxx.xxx, trying next server
Server: xxx.xxx.xxx.xxx
Address: xxx.xxx.xxx.xxx#53
Non-authoritative answer:
Name: bitcointalk.org
Address: 8.7.198.45
;; Got SERVFAIL reply from xxx.xxx.xxx.xxx, trying next server
Server: xxx.xxx.xxx.xxx
Address: xxx.xxx.xxx.xxx#53
Non-authoritative answer:
Name: bitcointalk.org
Address: 8.7.198.45
What is 8.7.198.45? Is it Bitcoin Forum's IDC?
If you're behind GFW that should be one of their fake addresses. GFW employs a DNS poisoning attack to hijack the location of blacklisted sites. That IP is a pretty common fake/misdirection IP that they use. You'll have to rely on external services to get the actual IP address for blocked sites.