Due to an unfortunate incident involving sleep mode and an overheated backpack I had the “opportunity” to rebuild my laptop. Since this meant reinstalling OpenStack I used this as an excuse to finally move to the ML2 network plugin for Neutron.

I was attempting to add an external network using the normal incantation:

neutron net-create external -- --router:external=true \
    --provider:network_type=flat \
    --provider:physical_network=physnet1

While this command completed successfully, I was left without any connectivity between br-int and br-ex, despite having in my /etc/neutron/plugins/ml2/ml2_conf.ini:

This is just here as a reminder for me:

An OVS interface has a variety of attributes associated with it, including an external-id field that can be used to associate resources outside of OpenVSwitch with the interface. You can view this field with the following command:

$ ovs-vsctl --columns=name,external-ids list Interface

Which on my system, with a single virtual instance, looks like this:

# ovs-vsctl --columns=name,external-ids list Interface
.
.
.
name                : "qvo519d7cc4-75"
external_ids        : {attached-mac="fa:16:3e:f7:75:b0", iface-id="519d7cc4-7593-4944-af7b-4056436f2d66", iface-status=active, vm-uuid="0330b084-03db-4d42-a231-2cd6ad89515b"}
.
.
.

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