On Tue, Sep 8, 2020 at 5:39 PM Alexander V. Chernikov <melifaro at freebsd.org> wrote: > - CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, NULL, 0, > + CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_MPSAFE, NULL, 0, Don't you still need CTLFLAG_RW? I don't believe that the sysctl is usable at all without it.