---
name: "vale"
section: "4freebsd"
platform: "linux"
package: "freebsd-manpages"
version: "12.2-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/vale/4freebsd"
---

# vale(4freebsd)

a very fast Virtual Local Ethernet using the netmap API

## NAME

**vale** – a very fast Virtual Local Ethernet using the netmap API

## SYNOPSIS

**device** **netmap**

## DESCRIPTION

**vale** is a feature of the [netmap(4)](/netmap/4.md) 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)](/netmap/4.md) 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)](/netmap/4.md) for details on the API.

### LIMITS

**vale** currently supports up to 8 switches, with 254 ports per switch.

## SYSCTL VARIABLES

See [netmap(4)](/netmap/4.md) for a list of sysctl variables that affect **vale** bridges.

## 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)](/netmap/4.md)

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).