I run "nslookup www.yahoo.com" in Windows 7.
It returns several results; some of them are IP=184.108.40.206 and alias=fd-fp3.wg1.b.yahoo.com
I tried to enter 220.127.116.11 and fd-fp3.wg1.b.yahoo.com, the former returns me a failure and the latter showed me yahoo webpage correctly.
I am wondering, since the IP 18.104.22.168 seems to be a valid IP (not like 192.168.x.x), why can't I just use it as a normal URL?
Which kind of technique or say, how can they block my access?