.\"	$NetBSD: xennet.4,v 1.4 2015/11/20 17:02:58 christos Exp $
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.\" by Jean-Yves Migeon <jym@NetBSD.org>.
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.Dd November 20, 2015
.Dt XENNET 4 xen
.Os
.Sh NAME
.Nm xennet
.Nd Xen frontend paravirtualized network interface
.Sh SYNOPSIS
.Cd "xennet* at xenbus?"
.Sh DESCRIPTION
The
.Nm
interface forms the frontend part of the paravirtualized drivers
used by
.Tn Xen
guest domains to have network connectivity.
.Pp
When the host domain is
.Nx ,
the endpoint of the
.Nm
interface is a
.Xr xvif 4
interface.
In the XenStore,
.Nm xvif
and
.Nm xennet
are identified by
.Dq vif
(virtual interface)
entries.
.Pp
Conceptually, frontends and backends drivers are
similar to two Ethernet cards connected via a crossover cable.
.Pp
.Nm xennet
interfaces can pass VLAN tagged packets.
.Sh DIAGNOSTICS
.Bl -diag
.It "xennet%d: can't read mac address, err %d"
The MAC address for this interface could not be read from XenStore.
.It "xennet%d: %s is not a valid mac address"
The MAC address specified in the configuration file of the newly
created guest domain is invalid.
.It "xennet%d: using event channel %d"
The
.Tn Xen
event channel (virtual interrupt) ID
associated to this
.Nm .
.It "xennet%d: using RX copy mode"
The
.Nm
and its associated endpoint use copy mode for communication: packets
are copied from one domain's memory to another.
.It "xennet%d: using RX flip mode"
The
.Nm
and its associated endpoint use flip mode for communication: packets
are passed by remapping memory pages between domains.
.El
.Sh SEE ALSO
.Xr bridge 4 ,
.Xr ifmedia 4 ,
.Xr xenbus 4 ,
.Xr xvif 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 3.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Manuel Bouyer Aq Mt bouyer@NetBSD.org
and
.An Christian Limpach Aq Mt chris@pin.lu .