Re: Can't create TCP connections to certain IP addresses

From: Anish Mistry <mistry.7_at_osu.edu>
Date: Mon, 20 Aug 2007 11:21:28 -0400
On Monday 20 August 2007, David Malone wrote:
> On Sun, Aug 19, 2007 at 05:51:14PM -0400, Anish Mistry wrote:
> > I'm not sure how to do that with the version of m0nowall that the
> > router is running.  But I can exhibit this behavior on the local
> > LAN without going through the router.
>
> In that case, run a tcpdump on both ends and see if the SYN packet
> is arriving at the far end. You might also want to try using
> "tcpdump -s0 -v" to check the checksums on the packets (though they
> can't always be trusted on the packet's sender if the network card
> supports checksum offloading).
>
> 	David.

There doesn't seem to be checksum offloading on the sender ath0
sender: tcpdump -s0 -v 
http://am-productions.biz/debug/littleguy.tcpdump.txt

Far end: tcpdump -s0 -v host 192.168.1.188
http://am-productions.biz/debug/bigguy.tcpdump.txt


-- 
Anish Mistry

Received on Mon Aug 20 2007 - 13:18:13 UTC

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