Hi, I'm the sysadmin at a 3500 customers ISP, wich runs an iptables+tc solution for load balancing and QoS. Every 2 or 3 weeks the server panics with a "NULL pointer dereference" and with IP at "dev_queue_xmit" It is curious that if i disable MSI on the network card driver this panics seems to disapear, does this ring a bell? The server is an IBM, previously with Broadcom NetXtreme II BCM5709 nics and now with Intel 82576. I change the nics thinking that maybe the bug was in Broadcom Driver but it seems to affect MSI in general. The tc+iptables rules are auto-generated with sequreisp[1] an ISP solution that i wrote and is open sourced under AGPLv3. Tell me if you need any further information, and plz CC because I'm not suscribed. root@server:~# uname -a Linux server 2.6.35-30-server #60~lucid1-Ubuntu SMP Tue Sep 20 22:28:40 UTC 2011 x86_64 GNU/Linux [1]https://github.com/sequre/sequreisp -- Luciano Ruete Sequre - Sys Admin Mitre 617, piso 7, of. 1 +54 261 4254894 Mendoza - Argentina http://www.sequre.com.ar/ http://www.sequreisp.com/