edsc —
Ethernet
discard network interface
device edsc
The
edsc interface is a software discard mechanism
which may be used for performance analysis and software testing. It imitates
an Ethernet device, which allows for its use in conjunction with such drivers
as
if_bridge(4) and
vlan(4).
As with other network interfaces, an
edsc interface
must have network addresses assigned for each address family with which it is
to be used. These addresses may be set or changed with the
SIOCSIFADDR
ioctl(2) or
ifconfig(8) utility.
Each
edsc interface 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).
ioctl(2),
arp(4),
if_bridge(4),
inet(4),
intro(4),
vlan(4),
rc.conf(5),
arp(8),
ifconfig(8)
The
edsc device was derived from the
disc(4) device and first appeared in
FreeBSD 6.3. This manpage was adapted from
disc(4).
Since outgoing packets are just discarded by
edsc,
ARP requests stay unreplied. Consequently, an IP packet cannot be sent via
edsc until a static
arp(4) entry is created for its next hop using
arp(8).
Initially an
edsc interface has a zero link level
address. It can be changed with
ifconfig(8)
lladdr if needed.