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Re: [Xen-users] trouble with TCP?

On Tue, Jun 21, 2005 at 12:35:43PM -0700, Nivedita Singhvi wrote:
> Can you tell where they were being dropped? Was netstat -s showing
> anything?  Have you tried different TCP apps? ftp, hping, rsync, ssh?
> Are you running IPSec or some other filtering?

I'm not running any ipsec, or iptables.  I'm not sure what to look for 
out of netstat -s.  (See attached.)  I didn't try other TCP apps, since 
it seemed to be down in the kernel (no ACK coming back).

> This is usually caused by a misconfiguration of the firewall
> or having some needed port not open.

That's what I had hoped, and I've trimmed it down to bare metal now.  
Originally I thought it was just related to bridging, and I totally 
removed that from the equation.

> Could you collect the ethereal or tcpdump trace of that happening, and also
> ifconfig, netstat -tan, netstat -s, sysctl -a, ip show rule, output?

Sure!  See attached.  It's got two directories, with the output from all 
mentioned commands (and route -n) along with xenU.pcap and xen0.pcap.  
To me, it just looks like xenU is just plain ignoring the SYN,ACK that 
comes in.  :(

Kees Cook                                            @outflux.net

Attachment: tcp-weirdness.tgz
Description: GNU Unix tar archive

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