NAME¶
epair
—
A pair of virtual back-to-back connected Ethernet
interfaces
SYNOPSIS¶
To compile this driver into the kernel, place the following line in your kernel
configuration file:
device epair
Alternatively, to load the driver as a module at boot time, place the following
line in
loader.conf(5):
DESCRIPTION¶
The
epair
is a pair of Ethernet-like software
interfaces, which are connected back-to-back with a virtual cross-over cable.
Each
epair
interface pair is created at
runtime using interface cloning. This is most easily done with the
ifconfig(8)
create
command or using the
cloned_interfaces variable in
rc.conf(5). While for cloning you only give
either
epair or
epair<n> the
epair
pair will be named like
epair<n>[ab]. This means the names of
the first
epair
interfaces will be
epair0a and
epair0b.
Like any other Ethernet interface, an
epair
needs to have a network address. Each
epair
will be assigned a locally administered address by default, that is only
guaranteed to be unique within one network stack. To change the default
addresses one may use the SIOCSIFADDR
ioctl(2) or
ifconfig(8) utility.
The basic intend is to provide connectivity between two virtual network stack
instances. When connected to a
if_bridge(4) one
end of the interface pair can also be part of another (virtual) LAN. As with
any other Ethernet interface one can configure
vlan(4) support on top of it.
SEE ALSO¶
ioctl(2),
altq(4),
bpf(4),
if_bridge(4),
vlan(4),
loader.conf(5),
rc.conf(5),
ifconfig(8)
HISTORY¶
The
epair
interface first appeared in
FreeBSD 8.0.
AUTHORS¶
The
epair
interface was written by
Bjoern A. Zeeb, CK Software GmbH, under
sponsorship from the FreeBSD Foundation.