xref: /openbsd/share/man/man4/options.4 (revision 898184e3)
1.\"	$OpenBSD: options.4,v 1.231 2013/03/22 16:40:24 deraadt Exp $
2.\"	$NetBSD: options.4,v 1.21 1997/06/25 03:13:00 thorpej Exp $
3.\"
4.\" Copyright (c) 1998 Theo de Raadt
5.\" Copyright (c) 1998 Todd Miller
6.\" Copyright (c) 1998 Gene Skonicki
7.\" Copyright (c) 1996
8.\" 	Perry E. Metzger.  All rights reserved.
9.\"
10.\" Redistribution and use in source and binary forms, with or without
11.\" modification, are permitted provided that the following conditions
12.\" are met:
13.\" 1. Redistributions of source code must retain the above copyright
14.\"    notice, this list of conditions and the following disclaimer.
15.\" 2. Redistributions in binary form must reproduce the above copyright
16.\"    notice, this list of conditions and the following disclaimer in the
17.\"    documentation and/or other materials provided with the distribution.
18.\" 3. All advertising materials mentioning features or use of this software
19.\"    must display the following acknowledgment:
20.\"	This product includes software developed for the NetBSD Project
21.\"	by Perry E. Metzger.
22.\" 4. The name of the author may not be used to endorse or promote products
23.\"    derived from this software without specific prior written permission.
24.\"
25.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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36.\"
37.Dd $Mdocdate: March 22 2013 $
38.Dt OPTIONS 4
39.Os
40.Sh NAME
41.Nm options
42.Nd kernel configuration options
43.Sh SYNOPSIS
44.Cd option ...
45.Sh DESCRIPTION
46This manual page describes a number of miscellaneous kernel
47configuration options that may be specified in a kernel config file.
48See
49.Xr config 8
50for information on how to configure and build kernels.
51.Em Note:
52options are passed to the compile process as
53.Fl D
54flags to the C compiler.
55.Sh COMPATIBILITY OPTIONS
56.Bl -ohang
57.It Cd option COMPAT_43
58This option enables compatibility with
59.Bx 4.3 .
60It adds ioctls for
61.Dv TIOCGETP
62and
63.Dv TIOCSETP .
64It also enables the deprecated
65.Dv NTTYDISC
66terminal line discipline.
67It provides backwards compatibility with the
68.Dq old
69SIOC[GS]IF{ADDR,DSTADDR,BRDADDR,NETMASK} interface ioctls, including
70binary compatibility for code written before the introduction of the
71.Li sa_len
72field in sockaddrs.
73.It Cd option COMPAT_LINUX
74On those architectures that support it, this enables binary
75compatibility with
76.Em Linux
77ELF and a.out
78applications built for the same architecture.
79This option is supported on the i386 architecture.
80See
81.Xr compat_linux 8 .
82.El
83.Sh DEBUGGING OPTIONS
84.Bl -ohang
85.It Cd makeoptions DEBUG="-g"
86The
87.Fl g
88flag causes
89.Pa bsd.gdb
90to be built in addition to
91.Pa bsd .
92.Pa bsd.gdb
93is useful for debugging kernels and their crash dumps with gdb.
94A crash dump can be debugged by starting
95.Xr gdb 1
96with the kernel name
97.Pf ( Pa bsd.gdb )
98as an argument (no core file) and then use the
99.Xr gdb 1
100command
101.Dq target kvm COREFILE .
102.It Cd makeoptions PROF="-pg"
103The
104.Fl pg
105flag causes the kernel to be compiled with support for profiling.
106The
107.Cm option GPROF
108is required for the kernel compile to succeed.
109.It Cd option ACCOUNTING
110Adds support for the
111.Xr acct 2
112system call.
113.It Cd option DDB
114Compiles in a kernel debugger for diagnosing kernel problems.
115See
116.Xr ddb 4
117for details.
118.It Cd option DDB_SAFE_CONSOLE
119Allows a break into the kernel debugger during boot.
120Useful when debugging problems that can cause
121.Xr init 8
122to fail.
123.It Cd option DDB_STRUCT
124Compiles in symbolic information about the various data structures used by the
125kernel, for use within the kernel debugger.
126This option is currently not supported on alpha, m68k, m88k and vax based
127platforms.
128.It Cd option DEBUG
129Turns on miscellaneous kernel debugging.
130Since options are turned into preprocessor defines (see above),
131.Cm option DEBUG
132is equivalent to doing a
133.Em #define DEBUG
134throughout the kernel.
135Much of the kernel has
136.Em #ifdef DEBUG
137conditional debugging code.
138Note that many parts of the kernel (typically device drivers) include their own
139.Em #ifdef XXX_DEBUG
140conditionals instead.
141This option also turns on certain other options, notably
142.Cm option KMEMSTATS .
143.It Cd option DIAGNOSTIC
144Adds code to the kernel that does internal consistency checks.
145This code will cause the kernel to panic if corruption of internal data
146structures is detected.
147.It Cd option GPROF
148Adds code to the kernel for kernel profiling with
149.Xr kgmon 8 .
150.It Cd option KGDB
151Compiles in a remote kernel debugger stub for diagnosing kernel problems
152using the
153.Dq remote target
154feature of gdb.
155See
156.Xr kgdb 7
157for details.
158.Em Note:
159not available on all architectures.
160.It Cd option KTRACE
161Adds hooks for the system call tracing facility, which allows users to
162watch the system call invocation behavior of processes.
163See
164.Xr ktrace 1
165for details.
166.It Cd option NO_PROPOLICE
167Do not compile the kernel with the ProPolice stack protection.
168See
169.Xr gcc-local 1
170for more information about ProPolice.
171.It Cd option PTRACE
172Adds hooks for the process tracing facility, allowing a process to
173control and observe another process.
174See
175.Xr ptrace 2
176for details.
177.It Cd option SMALL_KERNEL
178Removes some features and some optimizations from the kernel to reduce the
179size of the resulting kernel binary.
180This option is used on some installation media and should not be used
181for general purpose kernels.
182.It Cd option VFSLCKDEBUG
183Turns on debugging for the Virtual File System interface.
184See
185.Xr vfs 9
186for details.
187.El
188.Sh FILE SYSTEMS
189.Bl -ohang
190.It Cd option CD9660
191Includes code for the ISO 9660 + Rock Ridge file system, which is the
192standard file system used on many CD-ROMs.
193It also supports Joliet extensions.
194See
195.Xr mount_cd9660 8
196for details.
197.It Cd option EXT2FS
198Includes code implementing the Second Extended File System
199.Em ( EXT2FS ) ,
200commonly used on the Linux operating system.
201This option is provided here for compatibility.
202Some specific features of
203.Em EXT2FS
204like the "behavior on errors" are not implemented.
205This file system
206can't be used with
207.Li uid_t
208or
209.Li gid_t
210values greater than 65535.
211Also, the filesystem will not function correctly on architectures with
212differing byte-orders.
213That is, a big-endian machine will not be able to read an
214ext2fs filesystem created on an i386 or other little-endian machine.
215See
216.Xr mount_ext2fs 8
217for details.
218.It Cd option FFS
219Includes code implementing the Berkeley Fast File System
220.Em ( FFS ) .
221Most machines need this if they are not running diskless.
222.It Cd option FFS2
223Includes code implementing the enhanced Fast File System
224.Em ( FFS2 ) .
225.It Cd option MFS
226Include the memory file system
227.Em ( MFS ) .
228This file system stores files in swappable memory, and produces
229notable performance improvements when it is used as the file store
230for
231.Pa /tmp
232or similar mount points.
233See
234.Xr mount_mfs 8
235for details.
236.It Cd option MSDOSFS
237Includes support for the MS-DOS FAT file system.
238The kernel also implements the Windows 95
239extensions which permit the use of longer, mixed-case file names.
240See
241.Xr mount_msdos 8
242and
243.Xr fsck_msdos 8
244for details.
245.It Cd option NFSCLIENT
246Include the client side of the
247.Em NFS
248(Network File System) remote file sharing protocol.
249Although the bulk of the code implementing
250.Em NFS
251is kernel based, several user level daemons are needed for it to work.
252See
253.Xr mount_nfs 8
254for details on NFS.
255.It Cd option NTFS
256Includes support for reading NTFS file systems.
257See
258.Xr mount_ntfs 8
259for details.
260.It Cd option PROCFS
261Includes code for a special file system (conventionally mounted on
262.Pa /proc )
263in which the process space becomes visible in the file system.
264Among other things, the memory spaces of processes running on the system are
265visible as files, and signals may be sent to processes by writing to
266.Pa ctl
267files in the procfs namespace.
268See
269.Xr mount_procfs 8
270for details.
271.It Cd option UDF
272Includes code for the UDF file systems typically found on DVD discs.
273See
274.Xr mount_udf 8
275for details.
276.El
277.Sh FILE SYSTEM OPTIONS
278.Bl -ohang
279.It Cd option BUFCACHEPERCENT= Ns Ar integer
280Percentage of RAM to use as a file system buffer.
281It defaults to 5.
282.It Cd option EXT2FS_SYSTEM_FLAGS
283This option changes the behavior of the APPEND and IMMUTABLE flags
284for a file on an
285.Em EXT2FS
286filesystem.
287Without this option, the superuser or owner of the file can set and clear them.
288With this option, only the superuser can set them, and they can't be cleared
289if the securelevel is greater than 0.
290See also
291.Xr chflags 1 .
292.It Cd option FFS_SOFTUPDATES
293Enables a scheme that uses partial ordering of buffer cache operations
294to allow metadata updates in FFS to happen asynchronously, increasing write
295performance significantly.
296Normally, the FFS filesystem writes metadata updates synchronously which exacts
297a performance penalty in favor of filesystem integrity.
298With soft updates, the performance of asynchronous writes is gained while
299retaining the safety of synchronous metadata updates.
300.Pp
301Soft updates must be enabled on a per-filesystem basis.
302See
303.Xr mount 8
304for details.
305.Pp
306Processors with a small kernel address space, such as the sun4 and sun4c, do
307not have enough kernel memory to support soft updates.
308Attempts to use this option with these CPUs will cause a kernel hang or panic
309after a short period of use as the kernel will quickly run out of memory.
310This is not related to the amount of physical memory present in the machine --
311it is a limitation of the CPU architecture itself.
312.It Cd option FIFO
313Adds support for
314.At V
315style FIFOs (i.e.,
316.Dq named pipes ) .
317This option is recommended in almost all cases as many programs use these.
318.It Cd option NFSSERVER
319Include the server side of the
320.Em NFS
321(Network File System) remote file sharing protocol.
322Although the bulk of the code implementing
323.Em NFS
324is kernel based, several user level daemons are needed for it to
325work.
326See
327.Xr mountd 8
328and
329.Xr nfsd 8
330for details.
331.It Cd option QUOTA
332Enables kernel support for file system quotas.
333See
334.Xr quotaon 8 ,
335.Xr edquota 8 ,
336.Xr repquota 8 ,
337and
338.Xr quota 1
339for details.
340Note that quotas only work on
341.Dq ffs
342file systems, although
343.Xr rpc.rquotad 8
344permits them to be accessed over
345.Em NFS .
346.It Cd option UFS_DIRHASH
347This option enables using an in memory hash table to speed lookups
348in large directories.
349.El
350.Sh MISCELLANEOUS OPTIONS
351.Bl -ohang
352.It Cd option APERTURE
353Provide in-kernel support for controlling VGA framebuffer mapping
354and PCI configuration registers by user-processes
355(such as an X Window System server).
356This option is supported on the
357.Va alpha ,
358.Va amd64 ,
359.Va i386 ,
360.Va macppc ,
361and
362.Va sparc64
363architectures.
364.It Cd option BOOT_CONFIG
365Adds support for the
366.Fl c
367boot option (User Kernel Config).
368Allows modification of kernel settings (e.g., device parameters) before
369booting the system.
370.It Cd option CRYPTO
371Enables support for the kernel cryptographic framework.
372See
373.Xr crypto 9
374for details.
375While not IP specific, this option is usually used in conjunction with option
376.Em IPSEC .
377.It Cd option EISAVERBOSE
378Makes the boot process more verbose for EISA peripherals.
379.It Cd option INSECURE
380Hardwires the kernel security level at \-1.
381This means that the system always runs in securelevel 0 mode, even when
382running multiuser.
383See
384.Xr init 8
385for details on the implications of this.
386The kernel secure level may be manipulated by the superuser by altering the
387.Em kern.securelevel
388sysctl variable.
389(It should be noted that the securelevel may only be lowered by a call from
390process ID 1, i.e.,
391.Xr init 8 . )
392See also
393.Xr sysctl 8
394and
395.Xr sysctl 3 .
396.It Cd option KMEMSTATS
397The kernel memory allocator,
398.Xr malloc 9 ,
399will keep statistics on its performance if this option is enabled.
400Note that this option is silently turned on by the
401.Cm DEBUG
402option.
403.It Cd option LKM
404Enables support for loadable kernel modules.
405See
406.Xr lkm 4
407for details.
408.Em Note:
409This option is not yet available on all architectures.
410.It Cd option MACOBIOVERBOSE
411Makes the boot process more verbose for OBIO peripherals on the
412.Va macppc
413architecture.
414.It Cd option MULTIPROCESSOR
415On those architectures that have it, this enables multiprocessor support.
416.It Cd option PCIVERBOSE
417Makes the boot process more verbose for PCI peripherals
418(vendor names and other information is printed, etc.).
419.It Cd option PCMCIAVERBOSE
420Makes the boot process more verbose for PCMCIA peripherals.
421.It Cd option USER_LDT
422Enable userland manipulation of per-process
423Local Descriptor Table (LDT) entries;
424see
425.Xr i386_set_ldt 2
426and the
427.Va machdep.userldt
428.Xr sysctl 8 .
429This option is supported on the
430.Va i386
431architecture.
432.It Cd option USER_PCICONF
433Enables the user level access to the PCI bus configuration space
434through ioctls on the
435.Pa /dev/pci
436device.
437It's used by the
438.Xr Xorg 1
439server on some architectures.
440See
441.Xr pci 4
442for details.
443.It Cd option UVM_SWAP_ENCRYPT
444Enables kernel support for encrypting pages that are written out to
445swap storage.
446Swap encryption prevents sensitive data from remaining
447on the disk even after the operating system has been shut down.
448This option should be turned on if cryptographic filesystems are used.
449The sysctl variable
450.Em vm.swapencrypt.enable
451controls its behaviour.
452See
453.Xr sysctl 8
454and
455.Xr sysctl 3
456for details.
457.El
458.Sh NETWORKING OPTIONS
459.Bl -ohang
460.It Cd option ALTQ
461Enables ALTQ (Alternate Queuing).
462See
463.Xr pfctl 8
464and
465.Xr pf.conf 5
466to set up the interface transmission rate and queueing disciplines.
467.Em ALTQ_CBQ ,
468.Em ALTQ_RED ,
469.Em ALTQ_PRIQ
470and
471.Em ALTQ_HFSC
472are enabled by default with option
473.Em ALTQ
474in
475.Ox .
476See
477.Xr altq 9
478for details on ALTQ.
479.It Cd option ENCDEBUG
480This option enables debugging information to be conditionally logged
481in case IPSEC encounters errors.
482The option
483.Em IPSEC
484is required along with this option.
485Debug logging can be turned on/off through the use of the
486.Em net.inet.ip.encdebug
487sysctl variable.
488If
489.Em net.inet.ip.encdebug
490is 1, debug logging is on.
491See
492.Xr sysctl 8
493and
494.Xr sysctl 3
495for details.
496.It Cd option INET
497Includes support for the TCP/IP protocol stack.
498This option is currently required.
499See
500.Xr inet 4
501for details.
502.It Cd option INET6
503Includes support for the IPv6 protocol stack.
504See
505.Xr inet6 4
506for details.
507Unlike
508.Em INET ,
509.Em INET6
510enables multicast routing code as well.
511This option requires
512.Em INET
513at this moment, but it should not.
514.It Cd option IPSEC
515This option enables IP security protocol support.
516See
517.Xr ipsec 4
518for more details.
519.It Cd option KEY
520Enables PFKEYv2 (RFC 2367) support.
521While not IP specific, this option is usually used in conjunction with option
522.Em IPSEC .
523.It Cd option MROUTING
524Includes support for IP multicast routers.
525.Em INET
526should be set along with this.
527Multicast routing is controlled by the
528.Xr mrouted 8
529daemon.
530.It Cd option ND6_DEBUG
531The option sets the default value of
532.Em net.inet6.icmp6.nd6_debug
533to 1,
534for debugging IPv6 neighbor discovery protocol handling.
535See
536.Xr sysctl 3
537for details.
538.It Cd option PIPEX
539Includes pipex in-kernel acceleration for PPPoE, L2TP or PPTP.
540See
541.Xr pipex 4
542for details.
543.It Cd option PPP_BSDCOMP
544Enables BSD compressor for PPP connections.
545.It Cd option PPP_DEFLATE
546For use in conjunction with PPP_BSDCOMP; provides an interface to zlib for PPP
547for deflate compression/decompression.
548.It Cd option SOCKET_SPLICE
549Enables zero-copy socket splicing in the kernel.
550See
551.Dv SO_SPLICE
552in
553.Xr setsockopt 2
554and
555.Xr sosplice 9
556for details.
557.It Cd option TCP_ECN
558Turns on Explicit Congestion Notification (RFC 3168).
559.Em ECN
560allows intermediate routers to use the Congestion Experienced
561codepoint in the IP header as an indication of congestion, and allows
562TCP to adjust the transmission rate using this signal.
563Both communication endpoints negotiate enabling
564.Em ECN
565functionality at the TCP connection establishment.
566.It Cd option TCP_FACK
567Turns on forward acknowledgements allowing a more precise estimate of
568outstanding data during the fast recovery phase by using
569.Em SACK
570information.
571This option can only be used together with
572.Em TCP_SACK .
573.It Cd option TCP_SACK
574Turns on selective acknowledgements.
575Additional information about
576segments already received can be transmitted back to the sender,
577thus indicating segments that have been lost and allowing for
578a swifter recovery.
579Both communication endpoints need to support
580.Em SACK .
581The fallback behaviour is NewReno fast recovery phase, which allows
582one lost segment to be recovered per round trip time.
583When more than one segment has been dropped per window, the transmission can
584continue without waiting for a retransmission timeout.
585.It Cd option TCP_SIGNATURE
586Turns on support for the TCP MD5 Signature option (RFC 2385).
587This is used by
588Internet backbone routers to provide per-packet authentication for the TCP
589packets used to communicate BGP routing information.
590You will also need a
591routing daemon that supports this option in order to actually use it.
592.El
593.Sh OPERATION RELATED OPTIONS
594.Bl -ohang -compact
595.It Cd option BUFPAGES= Ns Ar value
596.It Cd option NBUF= Ns Ar value
597These options set the number of pages available for the buffer cache.
598Their default value is a machine dependent value, often calculated as
599between 5% and 10% of total available RAM.
600.Pp
601.It Cd option DST= Ns Ar value
602If
603.Ar value
604is non-zero, indicates that the hardware realtime clock device
605is one hour ahead of the offset given in
606.Sq TIMEZONE ,
607due to Daylight Saving Time (DST).
608If
609.Ar value
610is zero, the hardware realtime clock device is not in Daylight Saving Time.
611.Pp
612.It Cd option NKMEMPAGES= Ns Ar value
613.It Cd option NKMEMPAGES_MAX= Ns Ar value
614Size of kernel malloc area in PAGE_SIZE-sized logical pages.
615This area is covered by the kernel submap
616.Em kmem_map .
617The kernel attempts to auto-size this map based on the amount of
618physical memory in the system.
619Platform-specific code may place bounds on this computed size,
620which may be viewed with the
621.Xr sysctl 8
622variable
623.Em vm.nkmempages .
624See
625.Pa /usr/include/machine/param.h
626for the default upper bound.
627The related option
628.Sq NKMEMPAGES_MAX
629allows the bounds to be overridden in the kernel configuration file
630in the event the computed value is insufficient resulting in an
631.Dq out of space in kmem_map
632panic.
633.Pp
634.It Cd option \&"TIMEZONE= Ns Ar value Ns Cm \&"
635.Ar value
636indicates the time zone offset of the hardware realtime clock device,
637in minutes,
638from UTC.
639It is useful when the hardware realtime clock device is configured
640with local time,
641when dual-booting
642.Ox
643with other operating systems on a single machine.
644For instance, if the hardware realtime clock is set to Tokyo time,
645.Ar value
646should be
647.Li \&-540
648as Tokyo local time is 9 hours ahead of UTC.
649Double quotes are needed when specifying a negative
650.Ar value .
651.El
652.Sh SCSI SUBSYSTEM OPTIONS
653.Bl -ohang
654.It Cd option SCSI_DELAY= Ns Ar value
655Delay for
656.Ar value
657seconds before starting to probe the first SCSI bus.
658This can be used if a SCSI device needs extra time to get ready.
659.It Cd option SCSIDEBUG
660Enable printing of SCSI subsystem debugging info to the console.
661Each of
662.Em SCSIDEBUG_LEVEL ,
663.Em SCSIDEBUG_BUSES ,
664.Em SCSIDEBUG_TARGETS
665and
666.Em SCSIDEBUG_LUNS
667must have non-zero values for any debugging info to be printed.
668Only
669.Em SCSIDEBUG_LEVEL
670has a default value (SDEV_DB1 | SDEV_DB2) that is non-zero.
671.It Cd option SCSIDEBUG_BUSES= Ns Ar value
672Define which SCSI buses will print debug info.
673Each bit enables debugging info for the corresponding bus.
674e.g. a value of 0x1 enables debug info for bus 0.
675.It Cd option SCSIDEBUG_LEVEL= Ns Ar value
676Define which of the four levels of debugging info are printed.
677Each bit enables a level, and multiple levels are specified by setting multiple
678bits.
679.Bd -literal -offset indent
6800x0010	(SDEV_DB1) SCSI commands, errors, and data
6810x0020	(SDEV_DB2) routine flow
6820x0040	(SDEV_DB3) routine internals
6830x0080	(SDEV_DB4) miscellaneous addition debugging
684.Ed
685.Pp
686If
687.Em SCSIDEBUG_LEVEL
688is undefined, a value of 0x0030 (SDEV_DB1|SDEV_DB2) is used.
689.It Cd option SCSIDEBUG_LUNS= Ns Ar value
690Define which SCSI luns will print debug info.
691Each bit enables debugging info for the corresponding lun.
692.It Cd option SCSIDEBUG_TARGETS= Ns Ar value
693Define which SCSI targets will print debug info.
694Each bit enables debugging info for the corresponding target.
695.It Cd option SCSITERSE
696Terser SCSI error messages.
697This omits the table for decoding ASC/ASCQ info, saving about 30KB.
698.El
699.Sh SYSTEM V IPC OPTIONS
700.Bl -ohang
701.It Cd option SEMMNI= Ns Ar value
702Number of semaphore identifiers (also called semaphore handles
703and semaphore sets) available in the system.
704Default value is 10.
705The kernel allocates memory for the control structures at startup,
706so arbitrarily large values should be avoided.
707.It Cd option SEMMNS= Ns Ar value
708Maximum number of semaphores in all sets in the system.
709Default value is 60.
710.It Cd option SEMMNU= Ns Ar value
711Maximum number of semaphore undo structures in the system.
712Default value is 30.
713.It Cd option SEMUME= Ns Ar value
714Maximum number of per-process undo operation entries in the
715system.
716Semaphore undo operations are invoked by the kernel when
717.Xr semop 2
718is called with the SEM_UNDO flag and the process holding
719the semaphores terminates unexpectedly.
720Default value is 10.
721.It Cd option SHMMAXPGS= Ns Ar value
722Sets the maximum number of
723.At V
724style shared memory pages that are available through the
725.Xr shmget 2
726system call.
727Default value is 1024 on most architectures.
728See
729.Pa /usr/include/machine/vmparam.h
730for the default.
731.It Cd option SYSVMSG
732Includes support for
733.At V
734style message queues.
735See
736.Xr msgctl 2 ,
737.Xr msgget 2 ,
738.Xr msgrcv 2 ,
739.Xr msgsnd 2 .
740.It Cd option SYSVSEM
741Includes support for
742.At V
743style semaphores.
744See
745.Xr semctl 2 ,
746.Xr semget 2 ,
747.Xr semop 2 .
748.It Cd option SYSVSHM
749Includes support for
750.At V
751style shared memory.
752See
753.Xr shmat 2 ,
754.Xr shmctl 2 ,
755.Xr shmdt 2 ,
756.Xr shmget 2 .
757.El
758.Sh SEE ALSO
759.Xr intro 4 ,
760.Xr files.conf 5 ,
761.Xr config 8 ,
762.Xr sysctl 8
763.Sh HISTORY
764The
765.Nm
766man page first appeared in
767.Ox 2.3 .
768.Sh BUGS
769The
770.Em INET
771option should not be required.
772