dreyou's wiki

Load filter xml rules file from specified server while Vm start, then create and attach filter to virtual machine instance.

More info about libvirt's network filters http://libvirt.org/formatnwfilter.html

Define vm custom property:

snfilter=192.168.1.1:8080/filters,filtername

192.168.1.1:8080/filters - url of http server which holds xml nwfilter files, filtername - name of the filter file without “xml” extension.

Example content of filtername.xml

<filter name='filtername'>
  <filterref filter='clean-traffic'/>
  <rule action='accept' direction='in'>
      <tcp dstportstart='22'/>
  </rule>
  <rule action='accept' direction='in'>
      <tcp dstportstart='80'/>
   </rule>
  <rule action='accept' direction='out'>
      <tcp dstportstart='22'/>
  </rule>
  <rule action='accept' direction='out'>
      <tcp dstportstart='80'/>
  </rule>
  <rule action='accept' direction='out'>
      <icmp/>
  </rule>
  <rule action='accept' direction='out'>
      <udp dstportstart='53'/>
  </rule>
  <rule action='drop' direction='inout'>
      <all/>
   </rule>
</filter>

<note> <filter name='filtername'> must be same as filename i.e. if file name filtername.xml then filter name must be filtername </note>