freebsd/usr.sbin/ifmcstat/ifmcstat.8

.\"	$KAME: ifmcstat.8,v 1.6 2002/10/31 04:23:43 suz Exp $
.\"
.\" Copyright (c) 2007-2009 Bruce Simpson.
.\" Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project.
.\" All rights reserved.
.\"
.\" 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.
.\" 3. Neither the name of the project nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
.\" 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
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" 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.
.\"
.Dd May 27, 2009
.Dt IFMCSTAT 8
.Os
.Sh NAME
.Nm ifmcstat
.Nd dump multicast group management statistics per interface
.Sh SYNOPSIS
.Nm
.Op Fl i Ar interface
.Op Fl f Ar address-family
.Op Fl v
.Op Fl K
.Op Fl M Ar core
.Op Fl N Ar system
.\"
.Sh DESCRIPTION
The
.Nm
command dumps multicast group information from the kernel.
.Pp
The following options are supported:
.Bl -tag -width Fl
.It Fl i Ar interface
specifies the interface to be displayed.
.It Fl f Ar address-family
specifies the address family to be displayed;
.Ar inet ,
.Ar inet6
and
.Ar link
are supported.
.It Fl v
specifies that link-layer memberships should be printed;
they are suppressed by default.
It may not be specified for
.Fl f Ar link .
Source lists for each group will also be printed.
.Pp
If specified twice, and
.Xr kvm 3
is in use, the control plane timers for each interface
and the source list counters for each group
will also be printed.
.El
.Pp
The following options are only available if
.Nm
has been built with support for
.Xr kvm 3 :
.Bl -tag -width Fl
.It Fl K
attempts to use
.Xr kvm 3
to retrieve the multicast group information.
.It Fl M Ar core
extracts values associated with the name list from the specified core,
instead of the default
.Pa /dev/kmem .
.It Fl N Ar system
extracts the name list from the specified kernel instead of the
default, which is the kernel image the system has booted from.
.El
.Sh IMPLEMENTATION NOTES
.Nm
will always print the embedded scope IDs of IPv6 multicast group
memberships.
This is because memberships are always scoped to an interface.
.Pp
When run with the
.Fl v
option,
.Nm
may print multicast MAC addresses twice if they are
referenced by a layer 3 protocol.
.Pp
When run with
.Xr kvm 3
support,
the names of all interfaces configured in the system will be
printed in the first column of output, even if no multicast
group memberships are present on those interfaces.
The output may also be slightly different, as the kernel
data structures are being traversed with minimal post-processing
of the output.
.Pp
When built without
.Xr kvm 3
support, the information displayed by
.Nm
is more limited.
This support is recommended for debugging purposes.
It requires super-user privilege if used to inspect a running kernel.
.Sh SEE ALSO
.Xr netstat 1 ,
.Xr getifaddrs 3 ,
.Xr getifmaddrs 3 ,
.Xr kvm 3