Hi, I have last week discussed breakage in nwfilter usage on IRC <filterref filter='clean-traffic'> <parameter name='CTRL_IP_LEARNING' value='dhcp'/> </filterref> virsh start <guest> error: Failed to start domain <guest> error: internal error: applyDHCPOnlyRules failed - spoofing not protect With debug in the logs enabled I got confirmation by Daniel (thanks!) that the command sequence libvirt issued looked kind of "normal". Hereby I wanted to let you know that some further debugging identified a part of the sequence that libvirt issues as being broken in recent ebtables versions. # ebtables --concurrent -t nat -N testrule3 # ebtables --concurrent -t nat -E testrule3 testrule3-renamed ebtables v1.8.6 (nf_tables): Chain 'testrule3' doesn't exists This led to upstream ebtables bug [1] - for now just FYI in case you want/need to subscribe for your own tracking. [1]: https://bugzilla.netfilter.org/show_bug.cgi?id=1481 -- Christian Ehrhardt Staff Engineer, Ubuntu Server Canonical Ltd