vale (4)

Leading comments

Copyright (c) 2012 Luigi Rizzo, Universita` di Pisa
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   docume...

(The comments found at the beginning of the groff file "man4/vale.4freebsd".)

NAME

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

SYNOPSIS

device netmap

DESCRIPTION

ifconfig 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.

ifconfig 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

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

ifconfig 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

ifconfig 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

ifconfig 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)

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

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

AUTHORS

An -nosplit The ifconfig switch was designed and implemented in 2012 by An Luigi Rizzo and An Giuseppe Lettieri at the Universita` di Pisa.

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