Herbert Xu escribió: > These packets look like normal TSO packets. Linux will send a > packet containing more data than fits in a packet to the NIC. The > NIC will then segment the packet for us. > > If that is not possible, you can try disabling TSO with ethtool -K. I see... I have tracked the change to 2.6.18. Using kernel 2.6.17.14 and below makes tcpdump/libpcap to display the real packets. Could this be a change in the tg3 driver to support TSO committed in 2.6.18? And a question... how this TSO affects netfilter? > In order to see what really goes out, you'll need to run a packet > dump beyond the NIC. They are here: Sniffer traces taken through port mirroring in the switch (ethereal with filter: host flash.cnio.es): http://www.nimastelecom.com/smtptraces/smtptrace_portmirror.pcap But still wondering how could this affect Netfilter... my real problem is that Netfilter drops ACK packets because it doesn't see the connection established/related. I will try to do some more research. Regards, Carlos Velasco CCNP & CCDP Cisco Certified Network Professional - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html