Re: [libvirt-users] Adding a VLAN tag to a libvirt SR-IOV VF network using the "virsh net-update" command

On 07/11/2018 12:33 AM, Yegappan Lakshmanan wrote: Right. Because the <vlan> element in a network is not a part of the <bridge> element. It is a separate element all its own. the net-update command only supports updating a few very specific parts of the network definition, and the vlan element isn't one of those that's supported. I don't remember the chronology, but it's very likely that support for net-update was added before vlan tagging was supported, and that net-update support for it was either forgotten or deemed impractical to implement when vlan tag support was later added. Aha! This can be used to work around the absence of support for changing the <vlan> element directly under <network>. If the guest has "portgroup='blah'" in it's interface <source> element (or if the <portgroup> you change has "default='yes'", then any guest that is started after adding the portgroup should use the new vlan tag. However, the pre-existing interfaces of pre-existing guests will not have their vlan tag changed. Note that "virsh net-edit blah" is functionally the same as: virsh net-dumpxml blah --inactive >/tmp/blah.xml [modify /tmp/blah.xml] virsh net-define /tmp/blah.xml (and of course you'll have to net-destroy / net-start the network for the changes to take effect).