[systemd-devel] Systemd-networkd: Prepend static nameserver to DHCP-discovered nameservers

[David Timothy Strauss]

On Tue, Jun 17, 2014 at 4:33 AM, Mantas Mikulėnas <grawity at gmail.com> wrote:
> I mean, as long as the first-listed server responds – and localhost always
> responds – then the fallback servers won't be used at all.

Localhost can be subject to two types of failure:
 * The local daemon being down.
 * The resources the local daemon uses being inaccessible. It is
possible for root servers, for example, to be inaccessible while the
DHCP-issued nameservers can still be. Not all local daemons will
prefer to use the DHCP-issued nameservers as their upstream,
particularly if DNSSec is preferred/required.

Therefore, it can be useful to have a local daemon followed by
fallback to using the DHCP-issued nameservers.