[Samba] nmb.service fails on pure IPv6 system

[Jeremy Allison]

On Wed, Jul 26, 2023 at 01:13:57PM -0500, Tim Hoke via samba wrote:
>I have an IPv6 only system (no IPv4 addresses) and nmb.service goes into a
>failed state saying:
>
>Status: "nmbd: No local IPv4 non-loopback interfaces available, waiting for
>interface ..."
>
>I've seen several references to a previous bug where the service wasn't
>waiting
>for networking to be ready. That's _not_ my case here. Instead, I have no
>IPv4
>addresses, so I think it's stuck in the loop looking for non-loopback IPv4
>addresses.

nmbd is not IPv6 aware and can't serve IPv6 queries. Just disable
it on an IPv6-only box.