XENNET(4) | Device Drivers Manual (xen) | XENNET(4)

# 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 minimum 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>.

August 27, 2025 | NetBSD 11.99