On 2007-1-15 11:38 CST(UTC+8), Kevin Smith wrote: > When a page is blocked it usually looks like it has timed out. I'm not > clear as to how the blocking works. It seems that sensitive keywords > in a webpage trigger the firewall to send a TCP reset to both the > client and the server(1), but I do not know how specific IP addresses > are blocked. I guess the routers at the great firewall just stop the > client's request from reaching the server at that specific IP address > and that the router at the firewall doesn't send any response back to > the client so that it looks like a timeout. Someone please correct me > if I'm wrong about this. > > (1) > http://www.andrewlih.com/blog/2006/06/27/great-firewall-filtering-revealed/ > > Kevin S.
Probably nobody could clarify this issue, the Great Firewall is operated in the dark, almost all the work is based on reverse engineering, and to everyone's surprise, they even won't dare to admit the existence of the firewall. (http://news.com.com/China+We+dont+censor+the+Internet.+Really/2100-1028_3-6130970.html) Well, also please correct me if I'm wrong. :) Hanru P.S., Kevin, the full paper you mentioned is at: http://www.cl.cam.ac.uk/~rnc1/ignoring.pdf
