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VTNET(4)		    Kernel Interfaces Manual		      VTNET(4)

NAME
       vtnet --	VirtIO Ethernet	driver

SYNOPSIS
       To  compile  this  driver into the kernel, place	the following lines in
       your kernel configuration file:

	     device vtnet

       Alternatively, to load the driver as a module at	boot time,  place  the
       following line in loader.conf(5):

	     if_vtnet_load="YES"

DESCRIPTION
       The vtnet device	driver provides	support	for VirtIO Ethernet devices.

       If the hypervisor advertises the	appropriate features, the vtnet	driver
       supports	 TCP/UDP  checksum  offload for	both transmit and receive, TCP
       segmentation offload (TSO), TCP large receive offload  (LRO),  hardware
       VLAN tag	stripping/insertion features, a	multicast hash filter, as well
       as Jumbo	Frames (up to 9216 bytes), which can be	configured via the in-
       terface	MTU setting.  Selecting	an MTU larger than 1500	bytes with the
       ifconfig(8) utility configures the  adapter  to	receive	 and  transmit
       Jumbo Frames.

       For more	information on configuring this	device,	see ifconfig(8).

LOADER TUNABLES
       Tunables	 can  be set at	the loader(8) prompt before booting the	kernel
       or stored in loader.conf(5).

       hw.vtnet.csum_disable

       hw.vtnet.X.csum_disable
	       This tunable disables receive and send checksum	offload.   The
	       default value is	0.

       hw.vtnet.tso_disable

       hw.vtnet.X.tso_disable
	       This tunable disables TSO.  The default value is	0.

       hw.vtnet.lro_disable

       hw.vtnet.X.lro_disable
	       This tunable disables LRO.  The default value is	0.

       hw.vtnet.mq_disable

       hw.vtnet.X.mq_disable
	       This tunable disables multiqueue.  The default value is 0.

       hw.vtnet.mq_max_pairs

       hw.vtnet.X.mq_max_pairs
	       This  tunable  sets  the	maximum	number of transmit and receive
	       queue pairs.  Multiple queues are only supported	when the  Mul-
	       tiqueue	feature	is negotiated.	This driver supports a maximum
	       of 8 queue pairs.  The number of	queue pairs used is the	lesser
	       of the maximum supported	by the driver and the hypervisor,  the
	       number  of  CPUs	 present in the	guest, and this	tunable	if not
	       zero.  The default value	is 0.

SEE ALSO
       arp(4), netintro(4), ng_ether(4), virtio(4), vlan(4), ifconfig(8)

HISTORY
       The vtnet driver	was written by Bryan Venteicher	 <bryanv@FreeBSD.org>.
       It first	appeared in FreeBSD 9.0.

CAVEATS
       The  vtnet  driver only supports	LRO when the hypervisor	advertises the
       mergeable buffer	feature.

FreeBSD	13.2		       January 22, 2012			      VTNET(4)

NAME | SYNOPSIS | DESCRIPTION | LOADER TUNABLES | SEE ALSO | HISTORY | CAVEATS

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