How do I prevent BIND from stopping listening on an interface when it's temporarily down?

By default, BIND will scan the network interface list every 60 minutes and will stop listening on any interfaces that it finds unavailable when it runs this scan.

However, it's possible to configure the scanning interval and disable this functionality altogether if wished, using the interface-interval option in named.conf.

To disable interface scanning entirely (except when the configuration file is loaded), add the following to the options section of your configuration:

interface-interval 0;

The maximum configurable value is 28 days (40320 minutes).