DNS/KnotResolver/config/modeについて、ここに記述してください。

 mode('strict' | 'normal' | ‘permissive’)
    Returns:    Change resolver strictness checking level.

    By default, resolver runs in normal mode. There are possibly many small adjustments hidden behind the mode settings, but the main idea is that in permissive mode, the resolver tries to resolve a name with as few lookups as possible, while in strict mode it spends much more effort resolving and checking referral path. However, if majority of the traffic is covered by DNSSEC, some of the strict checking actions are counter-productive.

    Glue type           Modes when it is accepted       Example glue [1]
    mandatory glue      strict, normal, permissive      ns1.example.org
    in-bailiwick glue   normal, permissive              ns1.example2.org
    any glue records    permissive                      ns1.example3.net