/usr/bin/nsd-checkzone: invalid option -- '-'
Usage: nsd-checkzone [-p] <zone name> <zone file>
	-p	print the zone if the zone is ok
	-i <old zone file>	create an IXFR from the differences between the
		old zone file and the new zone file. Writes to
		<zonefile>.ixfr and renames other <zonefile>.ixfr files to
		<zonefile>.ixfr.num+1.
	-n <ixfr number>	number of IXFR versions to store, at most.
		default 5.
	-s <ixfr size>	size of IXFR to store, at most. default 1048576.
Version 4.15.4. Report bugs to <https://github.com/NLnetLabs/nsd/issues or nsd-bugs@nlnetlabs.nl>.