NAME

xennet — Xen frontend paravirtualized network interface

SYNOPSIS

xennet* at xenbus?

DESCRIPTION

The xennet interface forms the frontend part of the paravirtualized drivers used by Xen guest domains to have network connectivity.

When the host domain is NetBSD, the endpoint of the xennet interface is a xvif(4) interface. In the XenStore, xvif and xennet are identified by “vif” (virtual interface) entries.

Conceptually, frontends and backends drivers are similar to two Ethernet cards connected via a crossover cable.

xennet interfaces can pass VLAN tagged packets.

The minimum number of RX buffers can be controlled with the hw.xennet.xnfrx_lowat using the sysctl(8) utility. The default is to reserve no minumum number of cached RX buffers. A minimum number of reserved RX buffers can also be compiled into the kernel config using the XENNET_XNFRX_LOWAT option.

DIAGNOSTICS

xennet%d: can't read mac address, err %d

The MAC address for this interface could not be read from XenStore.

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.

xennet%d: using event channel %d

The Xen event channel (virtual interrupt) ID associated to this xennet.

xennet%d: using RX copy mode

The xennet and its associated endpoint use copy mode for communication: packets are copied from one domain's memory to another.

SEE ALSO

bridge(4), ifmedia(4), options(4), xenbus(4), xvif(4), ifconfig(8)

HISTORY

The xennet driver first appeared in NetBSD 3.0.

AUTHORS

The xennet driver was written by Manuel Bouyer <bouyer@NetBSD.org> and Christian Limpach <chris@pin.lu>.