IF_NTB(4)              FreeBSD Kernel Interfaces Manual              IF_NTB(4)

NAME
     if_ntb - Virtual Ethernet interface for Non-Transparent Bridges

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

           device ntb
           device ntb_transport
           device if_ntb

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

           if_ntb_load="YES"

     The following tunables are settable from the loader(8):

     hw.if_ntb.num_queues
     Limits maximal number of queues per interface.  Default is unlimited.

DESCRIPTION
     The if_ntb driver attaches on top of the ntb_transport(4) driver to
     utilize one or more of its packet queues to create virtual Ethernet
     network interface between the systems.  Typical MTU for the interface is
     about 64KB to reduce overhead.  Default MAC address for the interface is
     randomly generated.

     The if_ntb driver does not implement any real hardware offload, but since
     PCIe link is protected by CRC32, in some situations it may be possible to
     save some CPU cycles by enabling fake checksum offload on both link sides
     via setting rxcsum and txcsum interface options.

SEE ALSO
     ntb_transport(4)

AUTHORS
     The if_ntb driver was developed by Intel and originally written by Carl
     Delsey <carl@FreeBSD.org>.  Later improvements were done by Conrad E.
     Meyer <cem@FreeBSD.org> and Alexander Motin <mav@FreeBSD.org>.

BUGS
     Linux supports only one queue per interface, so manual configuration may
     be required for compatibility.

FreeBSD 13.1-RELEASE-p6        September 2, 2017       FreeBSD 13.1-RELEASE-p6