I use 'broadband'* from BSNL ISP in India. The plan I have currently comes with FUP (Fair Usage Policy). So I get 6GB (per month) at speed of 1Mbps and after 'fair' usage of 6GB, speed reduces to 512Kbps. Now once I reach the 6GB cap, my internet stops working temporarily and I get redirected to this [0] page everytime if I try to open any website and my downloads, torrents etc will be stopped. Any page will be directed to that page till I reboot my modem. Except HN. I don't really know why and how and certainly I cannot explain it. HN works even if I don't reboot my modem. I can make GET(loading HN), POST(comments, submissions) requests without any issues. I actually noticed this last month and I have tried to open many sites, but none of them would work, except, of course HN. I have confirmed with this my friend also, who uses services from same ISP.Is there anyway I can find out why other sites are blocked and why not HN? Can tools like Wireshark help me?
*yes, 1Mbps is also broadband in my country.
[0] - http://i.imgur.com/um8bTHz.png