<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=gb2312" http-equiv=Content-Type>
<STYLE>BLOCKQUOTE {
MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; MARGIN-LEFT: 2em
}
OL {
MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px
}
UL {
MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px
}
</STYLE>
<META name=GENERATOR content="MSHTML 8.00.6001.18812"></HEAD>
<BODY style="MARGIN: 10px">
<DIV><FONT color=#000080 size=2 face=Verdana>
<DIV><FONT size=2 face=Verdana>
<DIV><FONT color=#000000 size=2 face=Verdana></FONT> </DIV>
<DIV style="TEXT-INDENT: 2em"><FONT color=#000000>Seems that it's a weak point
of current Tor architecture. From a network manager's point of view, simply
blocking the Tor nodes posted in Tor directory
servers will infuence Tor users dramatically in the local
network. </FONT></DIV>
<DIV><FONT color=#000000></FONT> </DIV></FONT></FONT><FONT
color=#c0c0c0></DIV></DIV>
<DIV><FONT color=#000000 size=2 face=Verdana>
<TABLE width="100%">
<TBODY>
<TR>
<TD width="100%">
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV>Fyi</DIV>
<DIV></DIV>
<DIV>(For those of you who want to be on tor-relays, you can learn more about</DIV>
<DIV>it at https://www.torproject.org/documentation.html.en#MailingLists )</DIV>
<DIV></DIV>
<DIV>--Roger</DIV>
<DIV></DIV>
<DIV>----- Forwarded message from Roger Dingledine <arma@MIT.EDU> -----</DIV>
<DIV></DIV>
<DIV>From: Roger Dingledine <arma@MIT.EDU></DIV>
<DIV>To: tor-relays@torproject.org</DIV>
<DIV>Subject: Tor partially blocked in China; change your relay's IP address?</DIV>
<DIV>Delivery-Date: Wed, 30 Sep 2009 04:23:28 -0400</DIV>
<DIV></DIV>
<DIV>Hi folks,</DIV>
<DIV></DIV>
<DIV>China blocked about 80% of the public Tor relays last week:</DIV>
<DIV>https://blog.torproject.org/blog/tor-partially-blocked-china</DIV>
<DIV></DIV>
<DIV>They're really focused on circumvention tools this week in preparation</DIV>
<DIV>for their upcoming Oct 1:</DIV>
<DIV>http://en.wikipedia.org/wiki/National_Day_of_the_People's_Republic_of_China</DIV>
<DIV></DIV>
<DIV>Many bridges are still working fine, though they did block quite a few</DIV>
<DIV>of them too. Eventually it would be good to shift your Tor relay onto</DIV>
<DIV>an IP address that isn't blocked.</DIV>
<DIV></DIV>
<DIV>There are two ways that they're doing blocking. One is to filter your</DIV>
<DIV>whole IP address: no packets get in or out. You can check if this has</DIV>
<DIV>happened to you by trying to reach baidu.com from your IP address. The</DIV>
<DIV>other blocking approach is to send TCP reset packets when connections</DIV>
<DIV>are attempted to your IP:port. That's harder to check. I did a scan last</DIV>
<DIV>week from inside China, and I've put the result for your IP address up</DIV>
<DIV>at http://freehaven.net:8081/2009-09-24/<IP></DIV>
<DIV>e.g. http://freehaven.net:8081/2009-09-24/128.31.0.34</DIV>
<DIV></DIV>
<DIV>Note that the above URL includes answers about both known-blocked relays</DIV>
<DIV>and also known-blocked bridges.</DIV>
<DIV></DIV>
<DIV>It's possible that they'll remove the blocking all by themselves in a</DIV>
<DIV>few days, once Oct 1 passes. It's also possible they'll do another round</DIV>
<DIV>of blocking real soon now. Hard to say.</DIV>
<DIV></DIV>
<DIV>So if it's hard for you to get a new IP address, I recommend waiting</DIV>
<DIV>until at least next week. But if you have plenty to spare (or you're</DIV>
<DIV>on a cable/DSL system that will give you a new IP address if you just</DIV>
<DIV>poweroff your cable modem for a while), then now would be a fine time</DIV>
<DIV>to switch to a new one.</DIV>
<DIV></DIV>
<DIV>Remember that if you're on a multi-homed computer and moving to a</DIV>
<DIV>non-default IP, you will want to set both Address and OutboundBindAddress</DIV>
<DIV>in your torrc.</DIV>
<DIV></DIV>
<DIV>Thanks!</DIV>
<DIV>--Roger</DIV>
<DIV></DIV>
<DIV>----- End forwarded message -----</DIV>
<DIV></DIV>
<DIV>***********************************************************************</DIV>
<DIV>To unsubscribe, send an e-mail to majordomo@torproject.org with</DIV>
<DIV>unsubscribe or-talk in the body. <A
href="http://archives.seul.org/or/talk/">http://archives.seul.org/or/talk/</A></DIV></BLOCKQUOTE></TD></TR></TBODY></TABLE></FONT></DIV>
<DIV><FONT color=#000000 size=2 face=Verdana></FONT> </DIV>
<DIV><FONT color=#000000 size=2 face=Verdana>Allen
Ling</FONT></DIV></FONT></BODY></HTML>