In a DM it is needed to set explicitly the '-H' options, in ldb* tools and in samba-tool to a valid DC.
[This can be extended considering, in DC, the ability to point the -H option against the SAM database directly...]
But a domain can have many DC, and some of that can be currently not available (in maintenance, ...), and so script based on that tools can fail, while the domain effectively continue to works as expected.
Would be useful to have in that tool some sort of ''round robin'' or ''fallback'' against DC: eg, that tools determine the list of DCs (a simple DNS query), and choose the ''best and available'' one.
I hope i was clear. Thanks.