Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Typo in the EXAMPLES section: this is regexp, not a shell wildcard expression.

This is a direct commit to stable/9.

Submitted by: Ilya Noskov <phantom@phantom.su>

MFC r233648:
Remove trailing whitespace per mdoc lint warning

Approved by: cperciva (implicit)

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Fix a couple of issues in last commit.

Submitted by: maxim
Approved by: re (kib)

Describe how carp(4) status changes can be processed with
help of devd(8).

Submitted by: "Alexander V. Chernikov" <melifaro ipfw.ru>
Approved by: re (kib)

Complete the swap of carp(4) log levels and document the change.

MFC after: 3 days

Add section describing how ARP load balancing works and its
limitations:
- Can't load balance behind router
- ARP balancing + pfsync probably won't work

PR: kern/93829
Wording by: scottl

Typo: s/adverisement/advertisement/.

Submitted by: Fredrik Lindberg <fli+freebsd@shapeshifter.se>
PR: docs/85050

(Mostly) markup fixes.

Approved by: re (blanket)

- Document net.inet.carp.suppress_preempt MIB.
- Xref pfsync(4)

s/foobar/mekmitasdigoat/g

Requested by: ceri, des

- Be more informative about advbase and advskew. [1]
- Fix ifconfig commands. Replace 'mekmitasdigoat' with
'foobar'. While the former is more cool, the latter
makes example lines shorter.

Wording by: scottl
MFC after: 3 days

1. Annotate the rc.conf reference with a hint to the "cloned_interfaces"
variable, because it might be not obvious how to configure carp(4)
devices in rc.conf.

2. Remove the sentence about the not implemented "carpdev" option (this
was not imported from OpenBSD according to our source code) to avoid
confusion.

Reviewed by: glebius@
MFC after: 3 days

Update description of net.inet.carp.log

mdoc(7) cleanup

Submitted by: ru

Manpage for CARP from .Ox, with minor modifications.

Obtained from: OpenBSD