2005-02-23 08:29:50 +00:00
|
|
|
.\" $OpenBSD: carp.4,v 1.16 2004/12/07 23:41:35 jmc Exp $
|
|
|
|
|
.\"
|
|
|
|
|
.\" Copyright (c) 2003, Ryan McBride. All rights reserved.
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
.\" Copyright (c) 2011, Gleb Smirnoff <glebius@FreeBSD.org>
|
2005-02-23 08:29:50 +00:00
|
|
|
.\"
|
|
|
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
|
|
|
.\" modification, are permitted provided that the following conditions
|
|
|
|
|
.\" are met:
|
|
|
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
|
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
|
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
|
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
|
|
|
.\"
|
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
|
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|
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
|
|
|
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
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|
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
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|
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
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|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
|
.\" SUCH DAMAGE.
|
|
|
|
|
.\"
|
2005-02-24 09:43:16 +00:00
|
|
|
.\" $FreeBSD$
|
2005-02-23 08:29:50 +00:00
|
|
|
.\"
|
Restore a feature that was present in 5.x and 6.x, and was cleared in
7.x, 8.x and 9.x with pf(4) imports: pfsync(4) should suppress CARP
preemption, while it is running its bulk update.
However, reimplement the feature in more elegant manner, that is
partially inspired by newer OpenBSD:
- Rename term "suppression" to "demotion", to match with OpenBSD.
- Keep a global demotion factor, that can be raised by several
conditions, for now these are:
- interface goes down
- carp(4) has problems with ip_output() or ip6_output()
- pfsync performs bulk update
- Unlike in OpenBSD the demotion factor isn't a counter, but
is actual value added to advskew. The adjustment values for
particular error conditions are also configurable, and their
defaults are maximum advskew value, so a single failure bumps
demotion to maximum. This is for POLA compatibility, and should
satisfy most users.
- Demotion factor is a writable sysctl, so user can do
foot shooting, if he desires to.
2011-12-20 13:53:31 +00:00
|
|
|
.Dd December 20, 2011
|
2005-02-23 08:29:50 +00:00
|
|
|
.Dt CARP 4
|
|
|
|
|
.Os
|
|
|
|
|
.Sh NAME
|
|
|
|
|
.Nm carp
|
|
|
|
|
.Nd Common Address Redundancy Protocol
|
|
|
|
|
.Sh SYNOPSIS
|
|
|
|
|
.Cd "device carp"
|
|
|
|
|
.Sh DESCRIPTION
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
The CARP allows multiple hosts on the same local network to share a set of
|
|
|
|
|
IPv4 and/or IPv6 addresses.
|
2005-02-23 08:29:50 +00:00
|
|
|
Its primary purpose is to ensure that these
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
addresses are always available.
|
2005-02-23 08:29:50 +00:00
|
|
|
.Pp
|
|
|
|
|
To use
|
|
|
|
|
.Nm ,
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
the administrator needs to configure at minimum a common virtual host ID
|
|
|
|
|
(vhid) and attach at least one IP address to this vhid on each machine which
|
|
|
|
|
is to take part in the virtual group.
|
|
|
|
|
Additional parameters can also be set on a per-vhid basis:
|
2005-02-23 08:29:50 +00:00
|
|
|
.Cm advbase
|
|
|
|
|
and
|
|
|
|
|
.Cm advskew ,
|
|
|
|
|
which are used to control how frequently the host sends advertisements when it
|
|
|
|
|
is the master for a virtual host, and
|
|
|
|
|
.Cm pass
|
2005-02-24 09:43:16 +00:00
|
|
|
which is used to authenticate
|
|
|
|
|
.Nm
|
|
|
|
|
advertisements.
|
2005-04-07 14:20:34 +00:00
|
|
|
The
|
|
|
|
|
.Cm advbase
|
|
|
|
|
parameter stands for
|
2005-06-16 18:46:17 +00:00
|
|
|
.Dq "advertisement base" .
|
2005-08-17 18:43:07 +00:00
|
|
|
It is measured in seconds and specifies the base of the advertisement interval.
|
2005-04-07 14:20:34 +00:00
|
|
|
The
|
|
|
|
|
.Cm advskew
|
|
|
|
|
parameter stands for
|
2005-06-16 18:46:17 +00:00
|
|
|
.Dq "advertisement skew" .
|
2005-04-07 14:20:34 +00:00
|
|
|
It is measured in 1/256 of seconds.
|
|
|
|
|
It is added to the base advertisement interval to make one host advertise
|
|
|
|
|
a bit slower that the other does.
|
|
|
|
|
Both
|
|
|
|
|
.Cm advbase
|
|
|
|
|
and
|
|
|
|
|
.Cm advskew
|
2005-06-16 18:46:17 +00:00
|
|
|
are put inside CARP advertisements.
|
2005-02-23 08:29:50 +00:00
|
|
|
These configurations can be done using
|
|
|
|
|
.Xr ifconfig 8 ,
|
|
|
|
|
or through the
|
|
|
|
|
.Dv SIOCSVH
|
2005-02-24 09:43:16 +00:00
|
|
|
.Xr ioctl 2 .
|
2005-02-23 08:29:50 +00:00
|
|
|
.Pp
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
CARP virtual hosts can be configured on multicast capable interfaces: Ethernet,
|
|
|
|
|
layer 2 VLAN, FDDI and Token Ring.
|
|
|
|
|
An arbitrary number of virtual host IDs can be configured on an interface.
|
|
|
|
|
An arbitrary number of IPv4 or IPv6 addresses can be attached to a particular
|
|
|
|
|
vhid.
|
|
|
|
|
It is important that all hosts participating in a vhid have the same list
|
|
|
|
|
of prefixes configured on the vhid, since all prefixes are included in the
|
|
|
|
|
cryptographic checksum supplied in each advertisement.
|
|
|
|
|
Multiple vhids running on one interface participate in master/backup
|
|
|
|
|
elections independently.
|
|
|
|
|
.Pp
|
2005-02-23 08:29:50 +00:00
|
|
|
Additionally, there are a number of global parameters which can be set using
|
|
|
|
|
.Xr sysctl 8 :
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
.Bl -tag -width ".Va net.inet.carp.preempt"
|
2005-02-24 09:43:16 +00:00
|
|
|
.It Va net.inet.carp.allow
|
2005-02-23 08:29:50 +00:00
|
|
|
Accept incoming
|
|
|
|
|
.Nm
|
|
|
|
|
packets.
|
|
|
|
|
Enabled by default.
|
2005-02-24 09:43:16 +00:00
|
|
|
.It Va net.inet.carp.preempt
|
2005-02-23 08:29:50 +00:00
|
|
|
Allow virtual hosts to preempt each other.
|
|
|
|
|
It is also used to failover
|
|
|
|
|
.Nm
|
|
|
|
|
interfaces as a group.
|
|
|
|
|
When the option is enabled and one of the
|
|
|
|
|
.Nm
|
|
|
|
|
enabled physical interfaces
|
2005-02-24 09:43:16 +00:00
|
|
|
goes down,
|
|
|
|
|
.Cm advskew
|
|
|
|
|
is changed to 240 on all
|
2005-02-23 08:29:50 +00:00
|
|
|
.Nm
|
|
|
|
|
interfaces.
|
|
|
|
|
See also the first example.
|
|
|
|
|
Disabled by default.
|
2005-02-24 09:43:16 +00:00
|
|
|
.It Va net.inet.carp.log
|
2005-02-25 10:38:43 +00:00
|
|
|
Value of 0 disables any logging.
|
2010-01-08 16:14:41 +00:00
|
|
|
Value of 1 enables logging state changes of
|
2005-02-25 10:38:43 +00:00
|
|
|
.Nm
|
|
|
|
|
interfaces.
|
2010-01-08 16:14:41 +00:00
|
|
|
Values above 1 enable logging of bad
|
|
|
|
|
.Nm
|
|
|
|
|
packets.
|
2005-02-25 10:38:43 +00:00
|
|
|
Default value is 1.
|
Restore a feature that was present in 5.x and 6.x, and was cleared in
7.x, 8.x and 9.x with pf(4) imports: pfsync(4) should suppress CARP
preemption, while it is running its bulk update.
However, reimplement the feature in more elegant manner, that is
partially inspired by newer OpenBSD:
- Rename term "suppression" to "demotion", to match with OpenBSD.
- Keep a global demotion factor, that can be raised by several
conditions, for now these are:
- interface goes down
- carp(4) has problems with ip_output() or ip6_output()
- pfsync performs bulk update
- Unlike in OpenBSD the demotion factor isn't a counter, but
is actual value added to advskew. The adjustment values for
particular error conditions are also configurable, and their
defaults are maximum advskew value, so a single failure bumps
demotion to maximum. This is for POLA compatibility, and should
satisfy most users.
- Demotion factor is a writable sysctl, so user can do
foot shooting, if he desires to.
2011-12-20 13:53:31 +00:00
|
|
|
.It Va net.inet.carp.demotion
|
|
|
|
|
This value shows current level of CARP demotion.
|
|
|
|
|
The value is added to the actual advskew sent in announcements for
|
|
|
|
|
all vhids.
|
|
|
|
|
At normal system operation the demotion factor is zero.
|
|
|
|
|
However, problematic conditions raise its level: when
|
|
|
|
|
.Nm
|
|
|
|
|
experiences problem with sending announcements, when an interface
|
|
|
|
|
running a vhid goes down, or while the
|
2005-05-15 01:58:32 +00:00
|
|
|
.Xr pfsync 4
|
|
|
|
|
interface is not synchronized.
|
Restore a feature that was present in 5.x and 6.x, and was cleared in
7.x, 8.x and 9.x with pf(4) imports: pfsync(4) should suppress CARP
preemption, while it is running its bulk update.
However, reimplement the feature in more elegant manner, that is
partially inspired by newer OpenBSD:
- Rename term "suppression" to "demotion", to match with OpenBSD.
- Keep a global demotion factor, that can be raised by several
conditions, for now these are:
- interface goes down
- carp(4) has problems with ip_output() or ip6_output()
- pfsync performs bulk update
- Unlike in OpenBSD the demotion factor isn't a counter, but
is actual value added to advskew. The adjustment values for
particular error conditions are also configurable, and their
defaults are maximum advskew value, so a single failure bumps
demotion to maximum. This is for POLA compatibility, and should
satisfy most users.
- Demotion factor is a writable sysctl, so user can do
foot shooting, if he desires to.
2011-12-20 13:53:31 +00:00
|
|
|
The demotion value is writable, so that user may alter it
|
|
|
|
|
depending on some external conditions, for example on status of some
|
|
|
|
|
daemon utility.
|
|
|
|
|
However, altering the value should be performed with care, do
|
|
|
|
|
not conflict with subsystems that adjust demotion factor
|
|
|
|
|
automatically:
|
|
|
|
|
.Nm
|
|
|
|
|
and
|
|
|
|
|
.Xr pfsync 4 .
|
|
|
|
|
.It Va net.inet.carp.ifdown_demotion_factor
|
|
|
|
|
Value added to
|
|
|
|
|
.Va net.inet.carp.demotion
|
|
|
|
|
when interface running a vhid goes down.
|
|
|
|
|
Default value is 240 (maximum advskew value).
|
|
|
|
|
.It Va net.inet.carp.senderr_demotion_factor
|
|
|
|
|
Value added to
|
|
|
|
|
.Va net.inet.carp.demotion
|
|
|
|
|
when
|
|
|
|
|
.Nm
|
|
|
|
|
experiences errors sending its announcements.
|
|
|
|
|
Default value is 240 (maximum advskew value).
|
2005-02-23 08:29:50 +00:00
|
|
|
.El
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
.\".Sh ARP level load balancing
|
|
|
|
|
.\"The
|
|
|
|
|
.\".Nm
|
|
|
|
|
.\"has limited abilities for load balancing the incoming connections
|
|
|
|
|
.\"between hosts in Ethernet network.
|
|
|
|
|
.\"For load balancing operation, one needs several CARP interfaces that
|
|
|
|
|
.\"are configured to the same IP address, but to a different vhids.
|
|
|
|
|
.\"Once an ARP request is received, the CARP protocol will use a hashing
|
|
|
|
|
.\"function against the source IP address in the ARP request to determine
|
|
|
|
|
.\"which vhid should this request belong to.
|
|
|
|
|
.\"If the corresponding CARP interface is in master state, the ARP request
|
|
|
|
|
.\"will be replied, otherwise it will be ignored.
|
|
|
|
|
.\"See the
|
|
|
|
|
.\".Sx EXAMPLES
|
|
|
|
|
.\"section for a practical example of load balancing.
|
|
|
|
|
.\".Pp
|
|
|
|
|
.\"The ARP load balancing has some limitations.
|
|
|
|
|
.\"First, ARP balancing only works on the local network segment.
|
|
|
|
|
.\"It cannot balance traffic that crosses a router, because the
|
|
|
|
|
.\"router itself will always be balanced to the same virtual host.
|
|
|
|
|
.\"Second, ARP load balancing can lead to asymmetric routing
|
|
|
|
|
.\"of incoming and outgoing traffic, and thus combining it with
|
|
|
|
|
.\".Xr pfsync 4
|
|
|
|
|
.\"is dangerous, because this creates a race condition between
|
|
|
|
|
.\"balanced routers and a host they are serving.
|
|
|
|
|
.\"Imagine an incoming packet creating state on the first router, being
|
|
|
|
|
.\"forwarded to its destination, and destination replying faster
|
|
|
|
|
.\"than the state information is packed and synced with the second router.
|
|
|
|
|
.\"If the reply would be load balanced to second router, it will be
|
|
|
|
|
.\"dropped due to no state.
|
2011-08-15 12:08:41 +00:00
|
|
|
.Sh STATE CHANGE NOTIFICATIONS
|
|
|
|
|
Sometimes it is useful to get notified about
|
|
|
|
|
.Nm
|
|
|
|
|
status change events.
|
|
|
|
|
This can be accomplished by using
|
|
|
|
|
.Xr devd 8
|
|
|
|
|
hooks.
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
Master/slave events are signalled under system
|
|
|
|
|
.Dv CARP .
|
|
|
|
|
Subsystem specifies vhid and name of interface, where event occured.
|
|
|
|
|
Type of the message displays new state of vhid.
|
2011-08-15 12:08:41 +00:00
|
|
|
Please see
|
|
|
|
|
.Xr devd.conf 5
|
|
|
|
|
and
|
|
|
|
|
.Sx EXAMPLES
|
|
|
|
|
section for more information.
|
2005-02-23 08:29:50 +00:00
|
|
|
.Sh EXAMPLES
|
|
|
|
|
For firewalls and routers with multiple interfaces, it is desirable to
|
|
|
|
|
failover all of the
|
|
|
|
|
.Nm
|
|
|
|
|
interfaces together, when one of the physical interfaces goes down.
|
|
|
|
|
This is achieved by the preempt option.
|
|
|
|
|
Enable it on both host A and B:
|
|
|
|
|
.Pp
|
2005-02-24 09:43:16 +00:00
|
|
|
.Dl sysctl net.inet.carp.preempt=1
|
2005-02-23 08:29:50 +00:00
|
|
|
.Pp
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
Assume that host A is the preferred master and we are running the
|
|
|
|
|
192.168.1.0/24 prefix on em0 and 192.168.2.0/24 on em1.
|
2005-02-23 08:29:50 +00:00
|
|
|
This is the setup for host A:
|
|
|
|
|
.Bd -literal -offset indent
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
ifconfig em0 vhid 1 pass mekmitasdigoat 192.168.1.1/24
|
|
|
|
|
ifconfig em1 vhid 2 pass mekmitasdigoat 192.168.2.1/24
|
2005-02-23 08:29:50 +00:00
|
|
|
.Ed
|
|
|
|
|
.Pp
|
2005-02-24 09:43:16 +00:00
|
|
|
The setup for host B is identical, but it has a higher
|
|
|
|
|
.Cm advskew :
|
2005-02-23 08:29:50 +00:00
|
|
|
.Bd -literal -offset indent
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
ifconfig em0 vhid 1 advskew 100 pass mekmitasdigoat 192.168.1.1/24
|
|
|
|
|
ifconfig em1 vhid 2 advskew 100 pass mekmitasdigoat 192.168.2.1/24
|
2005-02-23 08:29:50 +00:00
|
|
|
.Ed
|
|
|
|
|
.Pp
|
|
|
|
|
Because of the preempt option, when one of the physical interfaces of
|
2005-02-24 09:43:16 +00:00
|
|
|
host A fails,
|
|
|
|
|
.Cm advskew
|
|
|
|
|
is adjusted to 240 on all its
|
2005-02-23 08:29:50 +00:00
|
|
|
.Nm
|
|
|
|
|
interfaces.
|
|
|
|
|
This will cause host B to preempt on both interfaces instead of
|
|
|
|
|
just the failed one.
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
.\".Pp
|
|
|
|
|
.\"In order to set up an ARP balanced virtual host, it is necessary to configure
|
|
|
|
|
.\"one virtual host for each physical host which would respond to ARP requests
|
|
|
|
|
.\"and thus handle the traffic.
|
|
|
|
|
.\"In the following example, two virtual hosts are configured on two hosts to
|
|
|
|
|
.\"provide balancing and failover for the IP address 192.168.1.10.
|
|
|
|
|
.\".Pp
|
|
|
|
|
.\"First the
|
|
|
|
|
.\".Nm
|
|
|
|
|
.\"interfaces on host A are configured.
|
|
|
|
|
.\"The
|
|
|
|
|
.\".Cm advskew
|
|
|
|
|
.\"of 100 on the second virtual host means that its advertisements will be sent
|
|
|
|
|
.\"out slightly less frequently.
|
|
|
|
|
.\".Bd -literal -offset indent
|
|
|
|
|
.\"ifconfig carp0 create
|
|
|
|
|
.\"ifconfig carp0 vhid 1 pass mekmitasdigoat 192.168.1.10/24
|
|
|
|
|
.\"ifconfig carp1 create
|
|
|
|
|
.\"ifconfig carp1 vhid 2 advskew 100 pass mekmitasdigoat 192.168.1.10/24
|
|
|
|
|
.\".Ed
|
|
|
|
|
.\".Pp
|
|
|
|
|
.\"The configuration for host B is identical, except the
|
|
|
|
|
.\".Cm advskew
|
|
|
|
|
.\"is on virtual host 1 rather than virtual host 2.
|
|
|
|
|
.\".Bd -literal -offset indent
|
|
|
|
|
.\"ifconfig carp0 create
|
|
|
|
|
.\"ifconfig carp0 vhid 1 advskew 100 pass mekmitasdigoat 192.168.1.10/24
|
|
|
|
|
.\"ifconfig carp1 create
|
|
|
|
|
.\"ifconfig carp1 vhid 2 pass mekmitasdigoat 192.168.1.10/24
|
|
|
|
|
.\".Ed
|
|
|
|
|
.\".Pp
|
|
|
|
|
.\"Finally, the ARP balancing feature must be enabled on both hosts:
|
|
|
|
|
.\".Pp
|
|
|
|
|
.\".Dl sysctl net.inet.carp.arpbalance=1
|
|
|
|
|
.\".Pp
|
|
|
|
|
.\"When the hosts receive an ARP request for 192.168.1.10, the source IP address
|
|
|
|
|
.\"of the request is used to compute which virtual host should answer the request.
|
|
|
|
|
.\"The host which is master of the selected virtual host will reply to the
|
|
|
|
|
.\"request, the other(s) will ignore it.
|
|
|
|
|
.\".Pp
|
|
|
|
|
.\"This way, locally connected systems will receive different ARP replies and
|
|
|
|
|
.\"subsequent IP traffic will be balanced among the hosts.
|
|
|
|
|
.\"If one of the hosts fails, the other will take over the virtual MAC address,
|
|
|
|
|
.\"and begin answering ARP requests on its behalf.
|
2011-08-15 12:08:41 +00:00
|
|
|
.Pp
|
|
|
|
|
Processing of
|
|
|
|
|
.Nm
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
status change events can be set up by using the following devd.conf rule:
|
2011-08-15 12:08:41 +00:00
|
|
|
.Bd -literal -offset indent
|
|
|
|
|
notify 0 {
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
match "system" "CARP";
|
|
|
|
|
match "subsystem" "[0-9]+@";
|
|
|
|
|
match "type" "(MASTER|BACKUP)";
|
|
|
|
|
action "/root/carpcontrol.sh $subsystem $type";
|
2011-08-15 12:08:41 +00:00
|
|
|
};
|
|
|
|
|
.Ed
|
2005-02-23 08:29:50 +00:00
|
|
|
.Sh SEE ALSO
|
|
|
|
|
.Xr inet 4 ,
|
2005-05-15 01:58:32 +00:00
|
|
|
.Xr pfsync 4 ,
|
|
|
|
|
.Xr rc.conf 5 ,
|
2011-08-15 13:33:28 +00:00
|
|
|
.Xr devd.conf 5 ,
|
2005-06-16 18:46:17 +00:00
|
|
|
.Xr ifconfig 8 ,
|
2005-02-23 08:29:50 +00:00
|
|
|
.Xr sysctl 8
|
|
|
|
|
.Sh HISTORY
|
|
|
|
|
The
|
|
|
|
|
.Nm
|
|
|
|
|
device first appeared in
|
|
|
|
|
.Ox 3.5 .
|
|
|
|
|
The
|
|
|
|
|
.Nm
|
2005-02-24 09:43:16 +00:00
|
|
|
device was imported into
|
2005-02-23 08:29:50 +00:00
|
|
|
.Fx 5.4 .
|
A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.
The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.
ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.
To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]
The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.
Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!
PR: kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by: bz
Submitted by: bz [1]
2011-12-16 12:16:56 +00:00
|
|
|
In
|
|
|
|
|
.Fx 10
|
|
|
|
|
the
|
|
|
|
|
.Nm
|
|
|
|
|
was significantly rewritten, and is no longer a pseudo-interface.
|
