Hi, I am having a VDSM hook that use custom network filter: <filter name='isolatedprivatevlan-vdsm' chain='root'> <uuid>aca4bfab-432c-54ac-aa62-b76c328ebbf2</uuid> <filterref filter='clean-traffic'/> <rule action='drop' direction='out' priority='500'> <mac match='no' dstmacaddr='$GATEWAY_MAC'/> </rule> </filter> the filter file name is isolatedprivatevlan-vdsm.xml, and installed in: /etc/libvirt/nwfilter/isolatedprivatevlan-vdsm.xml when I try to use it in libvirt domain xml: <interface> ... <filterref filter="isolatedprivatevlan-rhevm"> <parameter name="GATEWAY_MAC" value="aa:aa:aa:aa:aa:aa"/> </filterref> </interface> I am getting the following error: Network filter not found: Could not find filter 'isolatedprivatevlan-rhevm' The hook was running but not at my current version: libvirt-0.9.4-17.el6.x86_64 I try to install nwfilter-define via virsh and the list command, nwfilter-list - I can see the custom filter but again the same error. any ideas? Thank you, Shahar Havivi.