freebsd man page for vale

VALE(4) 						   BSD Kernel Interfaces Manual 						   VALE(4)

NAME
     vale -- a very fast Virtual Local Ethernet using the netmap API

SYNOPSIS
     device netmap

DESCRIPTION
     vale is a feature of the netmap(4) module that implements multiple Virtual switches that can be used to interconnect netmap clients, includ-
     ing traffic sources and sinks, packet forwarders, userspace firewalls, and so on.

     vale is implemented completely in software, and is extremely fast.  On a modern machine it can move almost 20 Million packets per second
     (Mpps) per core with small frames, and about 70 Gbit/s with 1500 byte frames.

OPERATION
     vale dynamically creates switches and ports as clients connect to it using the netmap(4) API.

     vale ports are named vale[bdg:][port] where vale is the prefix indicating a VALE switch rather than a standard interface, bdg indicates a
     specific switch (the colon is a separator), and port indicates a port within the switch.  Bridge and port names are arbitrary strings, the
     only constraint being that the full name must fit within 16 characters.

     See netmap(4) for details on the API.

   LIMITS
     vale currently supports up to 4 switches, 16 ports per switch, with 1024 buffers per port.  These hard limits will be changed to sysctl vari-
     ables in future releases.

SYSCTL VARIABLES
     vale uses the following sysctl variables to control operation:

     dev.netmap.bridge	 The maximum number of packets processed internally in each iteration.	Defaults to 1024, use lower values to trade
			 latency with throughput.

     dev.netmap.verbose  Set to non-zero values to enable in-kernel diagnostics.

EXAMPLES
     Create one switch, with a traffic generator connected to one port, and a netmap-enabled tcpdump instance on another port:

	   tcpdump -ni vale-a:1 &
	   pkt-gen  -i vale-a:0 -f tx &

     Create two switches, each connected to two qemu machines on different ports.

	   qemu -net nic -net netmap,ifname=vale-1:a ... &
	   qemu -net nic -net netmap,ifname=vale-1:b ... &
	   qemu -net nic -net netmap,ifname=vale-2:c ... &
	   qemu -net nic -net netmap,ifname=vale-2:d ... &

SEE ALSO
     netmap(4)

     http://info.iet.unipi.it/~luigi/vale/

     Luigi Rizzo, Giuseppe Lettieri: VALE, a switched ethernet for virtual machines, June 2012, http://info.iet.unipi.it/~luigi/vale/

AUTHORS
     The vale switch was designed and implemented in 2012 by Luigi Rizzo and Giuseppe Lettieri at the Universita` di Pisa.

     vale was funded by the European Commission within FP7 Projects CHANGE (257422) and OPENLAB (287581).

BSD
								   July 27, 2012							       BSD