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, including 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 valeSSS:PPP where vale is the prefix indicating a VALE switch rather than a standard
       interface, SSS indicates a specific switch (the colon is a separator), and PPP indicates  a  port  within
       the switch.  Both SSS and PPP have the form [0-9a-zA-Z_]+ , the string cannot exceed IFNAMSIZ characters,
       and PPP cannot be the name of any existing OS network interface.

       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 variables 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 valea:1 &
             pkt-gen  -i valea:0 -f tx &

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

             qemu -net nic -net netmap,ifname=vale1:a ... &
             qemu -net nic -net netmap,ifname=vale1:b ... &
             qemu -net nic -net netmap,ifname=vale2:c ... &
             qemu -net nic -net netmap,ifname=vale2:d ... &

SEE ALSO

       netmap(4)

       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).

Debian                                            July 27, 2012                                          VALE(4)