Comment 2 for bug 1620332

So, we're using this validation for 2 purposes:

1. to make sure the introspected nodes don't get an unexpected DHCP response

To do that, we need to get the introspection interface which is defined in: /etc/ironic-inspector/inspector.conf.

It's the "dnsmasq_interface" value under the "firewall" (deprecated) or "discoverd" section. The default value is: "br-ctlplane".

Or we could read it from /etc/ironic-inspector/dnsmasq.conf

2. On the pacemaker network: if the nodes get an IP address from an unexpected DHCP server, Pacemaker will consider the node dead and will fence it.

I'm not sure where to find out that interface/network, though.