Add a guide for bridging a vm-instance VM onto a physically-routed VLAN
via a Linux bridge and a bridge-type NetworkAttachmentDefinition. The
overlay-only default does not cover the case where a VM must share a
broadcast domain with external hardware and take an address from that
VLAN's subnet.
Explain why macvlan is incompatible with KubeVirt bridge binding (macvlan
demultiplexes ingress by the child MAC while bridge binding puts the
guest MAC on the wire, so replies are dropped) and why a Linux bridge
works, then walk through the host bridge, the NAD, and assigning a static
guest address through cloud-init. Cover the dual-homed NIC layout, the
absence of networkData, and the post-recreate ARP staleness.
Assisted-By: Claude <noreply@anthropic.com>
Signed-off-by: Aleksei Sviridkin <f@lex.la>
