[TriLUG] Fedora Core 2 vs www.usenix.org

[Timothy A. Chagnon]

On Tue, 2004-08-10 at 18:20, Mike Johnson wrote:
> Try this:
> echo "0" >/proc/sys/net/ipv4/tcp_ecn
> 
> Some site don't like ECN (Explicit Congestion Notification).  I have no
> clue if this is your problem, or if ECN is even enabled in FC2, but it's
> worth a shot.

I tried that, but it didn't seem to work.  I compared ethereal captures
from an FC2 box that doesn't get through and an FC1 box that does.  
Here are the apparent differences.  Let us know if something looks
significant.

- FC2 does a DNS Standard Query AAAA before it's Standard Query A, then
also does a reverse PTR query after.  FC1 only does the std A.  Both end
up with the same IP though, so this shouldn't matter.
- During the first (and only) SYN;SYN,ACK;ACK sequence, FC2 asks for a
window scale of 7, FC1 asks for 0.  They seem to settle around the same,
though at 5888 for FC2 and 5840 for FC1 on the GET / packet.
- In the GET / packet, there are only a couple diffs in the User-agent
and Accept lines.  Here are the lines for reference:

FC1:
> User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040116\r\n
> Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,image/jpeg,image/gif;q=0.2,*/*;q=0.1\r\n

FC2:
> User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040803\r\n
> Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5\r\n

- Both FC1 and FC2 get identical ACK packets for the GET / packet.
After that though, FC2 gets absolutely nothing.  No more packets from
the server.

I only have a general knowledge of all this, but nothing stands out.

-Tim
-- 
Timothy A. Chagnon <tchagnon at futeki.net>
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