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mac_ifoff — interface silencing policy
To compile the interface silencing policy into your kernel, place the
following lines in your kernel configuration file:
Alternately, to load the interface silencing policy module at boot time,
place the following line in your kernel configuration file:
and in loader.conf(5):
The mac_ifoff interface silencing module allows administrators to enable
and disable incoming and outgoing data flow on system network interfaces
via the sysctl(8) interface.
To disable network traffic over the loopback (lo(4)) interface, set the
sysctl(8) OID security.mac.ifoff.lo_enabled to 0 (default 1).
To enable network traffic over other interfaces, set the sysctl(8) OID
security.mac.ifoff.other_enabled to 1 (default 0).
To allow BPF traffic to be received, even while other traffic is
disabled, set the sysctl(8) OID security.mac.ifoff.bpfrecv_enabled to 1
No labels are defined.
mac(4), mac_bsdextended(4), mac_lomac(4), mac_mls(4), mac_none(4),
mac_partition(4), mac_portacl(4), mac_seeotheruids(4), mac_test(4),
The mac_ifoff policy module first appeared in FreeBSD 5.0 and was
developed by the TrustedBSD Project.
This software was contributed to the FreeBSD Project by Network
Associates Labs, the Security Research Division of Network Associates
Inc. under DARPA/SPAWAR contract N66001-01-C-8035 (“CBOSS”), as part of
the DARPA CHATS research program.
See mac(9) concerning appropriateness for production use. The TrustedBSD
MAC Framework is considered experimental in FreeBSD.
While the MAC Framework design is intended to support the containment of
the root user, not all attack channels are currently protected by entry
point checks. As such, MAC Framework policies should not be relied on,
in isolation, to protect against a malicious privileged user.