Host network changes, all VMs lost network connectivity

Hi all!

I recently changed the underlying host network configuration (moving VLAN tagging from host to switch) and it seems to have completely blocked any sort of network connectivity for my VMs.

I run OpenNebula 5.4.6 on Ubuntu 16.04.

I have 4 physical network interfaces which used to be configured on the host as such:

auto br_admin
iface br_admin inet dhcp
    bridge_ports eno1
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

auto br_service
iface br_service inet dhcp
    bridge_ports eno2
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

auto eno2.20
iface eno2.20 inet manual

auto eno2.30
iface eno2.30 inet manual

auto br_public
iface br_service inet dhcp
    bridge_ports eno2.20
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

auto br_data
iface br_service inet dhcp
    bridge_ports eno2.30
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

I was able to move the VLAN bridges onto separate interfaces, not that the other two bridges went unmodified…

auto br_admin
iface br_admin inet dhcp
    bridge_ports eno1
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

auto br_service
iface br_service inet dhcp
    bridge_ports eno2
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

auto br_public
iface br_service inet dhcp
    bridge_ports eno3
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

auto br_data
iface br_service inet dhcp
    bridge_ports eno4
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

None of my VMs use br_public or br_data, and they do not form any part of the OpenNebula config, so I was very shocked when I found my VMs had lost connectivity after this change. I rebooted all the VMs and later the host, but the problem persists.

I deleted and recreated the Virtual Networks within OpenNebula and detached the old nics, and adding new ones to the VMs. Even create entirely new VMs from scratch and I can’t seem to get any network connection back.

Any ideas?? Thanks in advance…