Thanks Graig for your reply. I suspected it. I disabled TCP offload using ethtool but nothing changed. below is the ethtool output:
sudo ethtool -k eth0 Offload parameters for eth0: rx-checksumming: off tx-checksumming: off scatter-gather: off tcp-segmentation-offload: off udp-fragmentation-offload: off generic-segmentation-offload: off generic-receive-offload: on large-receive-offload: off rx-vlan-offload: on tx-vlan-offload: on ntuple-filters: off receive-hashing: off Thanks, > Subject: RE: TCP checksum not transmited to the wire! > Date: Mon, 28 Jan 2013 11:22:22 -0500 > From: [email protected] > To: [email protected] > CC: [email protected] > > Many server-grade systems these days have TCP checksum offloads. Could > this be what you're seeing? > > Craig Jackson > > _______________________________________________ > Kernelnewbies mailing list > [email protected] > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
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