Hi, I have created ticket http://bugs.centos.org/view.php?id=1476 After upgrade to 4.4, tc is not working with htb anymore. Probably tc is not compiled with htb support. iproute-2.6.9-3.EL4.3: Error: Qdisc "htb" is classless. Unknown filter "fw", hence option "flowid" is unparsable iproute-2.6.9-3: works fine workaround: use /sbin/tc from old package Regards, David Hrbáč