Explicitly use an empty 'trust-anchors' statement in the system
tests where it was used implicitly before.
In resolver/ns5/named.conf.in use the trust anchor in 'trusted.conf',
which was supposed to be used there.
The lock-file configuration (both from configuration file and -X
argument to named) has better alternatives nowadays. Modern process
supervisor should be used to ensure that a single named process is
running on a given configuration.
Alternatively, it's possible to wrap the named with flock(1).
Create a zone that triggers DNAME owner name checks in a zone that
is only reachable using a dual stack server. The answer contains
a name that is higher in the tree than the query name.
e.g.
foo.v4only.net. CNAME v4only.net.
v4only.net. A 10.0.0.1
ns4 is serving the test zone (ipv4-only)
ns6 is the root server for this test (dual stacked)
ns7 is acting as the dual stack server (dual stacked)
ns9 is the server under test (ipv6-only)
