<s>
Solaris	B-Protocol
network	I-Protocol
virtualization	I-Protocol
and	I-Protocol
resource	I-Protocol
control	I-Protocol
is	O
a	O
set	O
of	O
features	O
originally	O
developed	O
by	O
Sun	O
Microsystems	O
as	O
the	O
OpenSolaris	B-Operating_System
Crossbow	O
umbrella	O
project	O
,	O
providing	O
an	O
internal	O
network	B-Protocol
virtualization	I-Protocol
and	O
quality	O
of	O
service	O
framework	O
within	O
the	O
Solaris	B-Application
Operating	I-Application
System	I-Application
.	O
</s>
<s>
The	O
Crossbow	O
project	O
software	O
,	O
combined	O
with	O
next	O
generation	O
network	O
interfaces	O
like	O
xge	O
and	O
bge	O
,	O
enable	O
network	B-Protocol
virtualization	I-Protocol
and	O
resource	O
control	O
for	O
a	O
single	O
system	O
.	O
</s>
<s>
By	O
combining	O
VNICs	B-Protocol
with	O
features	O
such	O
as	O
or	O
the	O
Sun	O
xVM	O
hypervisor	O
,	O
system	O
administrators	O
can	O
run	O
applications	O
on	O
separate	O
virtual	B-Architecture
machines	I-Architecture
to	O
improve	O
performance	O
and	O
provide	O
security	O
.	O
</s>
<s>
Resource	O
management	O
and	O
flow	O
control	O
features	O
provide	O
bandwidth	O
management	O
and	O
quality	O
of	O
service	O
for	O
packet	O
flows	O
on	O
separate	O
virtual	B-Architecture
machines	I-Architecture
.	O
</s>
<s>
You	O
can	O
allocate	O
bandwidth	O
amounts	O
and	O
manage	O
data	O
flows	O
not	O
only	O
for	O
the	O
physical	B-Protocol
network	I-Protocol
interface	I-Protocol
but	O
also	O
for	O
any	O
containers	O
configured	O
on	O
the	O
interface	O
.	O
</s>
<s>
The	O
Crossbow	O
resource	O
control	O
features	O
enable	O
increased	O
system	O
efficiency	O
and	O
the	O
ability	O
to	O
limit	O
the	O
amount	O
of	O
bandwidth	O
consumed	O
by	O
a	O
process	O
or	O
virtual	B-Architecture
machine	I-Architecture
.	O
</s>
<s>
This	O
section	O
briefly	O
describes	O
the	O
main	O
features	O
of	O
the	O
Crossbow	O
network	B-Protocol
virtualization	I-Protocol
and	O
resource	O
control	O
project	O
.	O
</s>
<s>
For	O
further	O
details	O
on	O
each	O
feature	O
,	O
see	O
the	O
Oracle	B-Application
Solaris	I-Application
11	O
Network	B-Protocol
Virtualization	I-Protocol
and	O
Network	O
Resource	O
Management	O
white	O
paper	O
.	O
</s>
<s>
A	O
VNIC	B-Protocol
is	O
a	O
pseudo	O
network	O
interface	O
that	O
is	O
configured	O
on	O
top	O
of	O
a	O
system	O
's	O
physical	O
network	B-Protocol
adapter	I-Protocol
,	O
also	O
called	O
a	O
network	B-Protocol
interface	I-Protocol
controller	I-Protocol
(	O
NIC	O
)	O
.	O
</s>
<s>
A	O
physical	O
interface	O
can	O
have	O
more	O
than	O
one	O
VNIC	B-Protocol
.	O
</s>
<s>
Each	O
VNIC	B-Protocol
operates	O
like	O
and	O
appears	O
to	O
the	O
system	O
as	O
a	O
physical	O
NIC	O
.	O
</s>
<s>
The	O
individual	O
VNIC	B-Protocol
is	O
assigned	O
a	O
media	O
access	O
control	O
address	O
(	O
MAC	O
address	O
)	O
,	O
which	O
can	O
be	O
configured	O
to	O
a	O
value	O
other	O
than	O
the	O
default	O
MAC	O
address	O
assigned	O
to	O
the	O
physical	O
NIC	O
.	O
</s>
<s>
You	O
can	O
use	O
the	O
resource	O
control	O
features	O
of	O
Crossbow	O
to	O
allocate	O
separate	O
bandwidths	O
to	O
the	O
individual	O
VNICs	B-Protocol
.	O
</s>
<s>
Moreover	O
,	O
you	O
can	O
configure	O
a	O
virtual	B-Architecture
machine	I-Architecture
,	O
such	O
as	O
an	O
exclusive	O
IP	O
zone	O
or	O
xVM	O
domain	O
on	O
top	O
of	O
a	O
VNIC	B-Protocol
.	O
</s>
<s>
When	O
the	O
first	O
VNIC	B-Protocol
is	O
created	O
on	O
a	O
system	O
,	O
a	O
virtual	O
switch	O
is	O
also	O
created	O
above	O
the	O
physical	O
interface	O
.	O
</s>
<s>
Though	O
not	O
directly	O
accessible	O
to	O
the	O
user	O
,	O
the	O
virtual	O
switch	O
provides	O
connectivity	O
between	O
all	O
VNICs	B-Protocol
configured	O
on	O
the	O
same	O
physical	O
interface	O
,	O
enabling	O
the	O
virtual	B-Protocol
network	I-Protocol
in	O
a	O
box	O
scenario	O
.	O
</s>
<s>
The	O
virtual	O
switch	O
forwards	O
packets	O
between	O
the	O
system	O
's	O
VNICs	B-Protocol
.	O
</s>
<s>
Thus	O
,	O
packets	O
from	O
an	O
internal	O
VNIC	B-Protocol
source	O
never	O
have	O
to	O
pass	O
to	O
the	O
external	O
network	O
to	O
reach	O
an	O
internal	O
network	O
destination	O
.	O
</s>
<s>
Each	O
exclusive	O
IP	O
zone	O
is	O
built	O
upon	O
a	O
physical	B-Protocol
network	I-Protocol
interface	I-Protocol
and	O
has	O
its	O
own	O
IP-related	O
state	O
.	O
</s>
<s>
In	O
Solaris	B-Application
,	O
the	O
MAC	O
layer	O
is	O
part	O
of	O
the	O
larger	O
data	B-Protocol
link	I-Protocol
layer	I-Protocol
of	O
the	O
TCP/IP	O
protocol	O
stack	O
.	O
</s>
<s>
However	O
,	O
the	O
MAC	O
client	O
interface	O
along	O
with	O
the	O
VNIC	B-Protocol
driver	O
provides	O
the	O
VNIC	B-Protocol
functionality	O
in	O
OpenSolaris	B-Operating_System
.	O
</s>
<s>
Additionally	O
,	O
Crossbow	O
modifications	O
to	O
the	O
MAC	O
layer	O
enable	O
a	O
system	O
administrator	O
to	O
assign	O
a	O
different	O
MAC	O
address	O
to	O
each	O
VNIC	B-Protocol
on	O
a	O
system	O
.	O
</s>
<s>
The	O
Crossbow	O
project	O
features	O
provide	O
bandwidth	O
management	O
and	O
flow	O
control	O
on	O
a	O
per	O
VNIC	B-Protocol
basis	O
.	O
</s>
<s>
A	O
system	O
administrator	O
can	O
configure	O
different	O
bandwidth	O
allocations	O
to	O
the	O
various	O
VNICs	B-Protocol
on	O
a	O
host	O
through	O
the	O
new	O
Crossbow-related	O
commands	O
and	O
.	O
</s>
<s>
Traffic	O
through	O
each	O
VNIC	B-Protocol
can	O
be	O
classified	O
and	O
separated	O
into	O
individual	O
flows	O
,	O
based	O
on	O
port	O
number	O
,	O
destination	O
IP	O
address	O
,	O
and	O
other	O
parameters	O
.	O
</s>
<s>
These	O
features	O
can	O
be	O
used	O
to	O
improve	O
system	O
efficiency	O
and	O
enable	O
differentiated	O
services	O
for	O
separate	O
VNICs	B-Protocol
.	O
</s>
<s>
Standard	O
Solaris	B-Application
observability	O
tools	O
can	O
be	O
used	O
to	O
monitor	O
the	O
status	O
of	O
exclusive	O
IP	O
instances	O
,	O
VNICs	B-Protocol
,	O
and	O
virtual	B-Architecture
machines	I-Architecture
running	O
on	O
VNICs	B-Protocol
.	O
</s>
<s>
For	O
example	O
,	O
familiar	O
tools	O
such	O
as	O
ping	B-Protocol
and	O
snoop	B-Protocol
can	O
report	O
status	O
on	O
the	O
operations	O
of	O
a	O
VNIC	B-Protocol
.	O
</s>
<s>
The	O
exclusive	O
IP	O
zones	O
feature	O
was	O
first	O
introduced	O
in	O
the	O
Solaris	B-Application
10	I-Application
8/07	O
release	O
.	O
</s>
<s>
The	O
first	O
version	O
of	O
the	O
Crossbow	O
feature	O
set	O
was	O
incorporated	O
in	O
OpenSolaris	B-Operating_System
2009.06	O
.	O
</s>
<s>
The	O
full	O
Crossbow	O
feature	O
set	O
became	O
part	O
of	O
Solaris	B-Application
with	O
the	O
2011	O
release	O
of	O
Solaris	B-Application
11	I-Application
.	O
</s>
<s>
Oracle	B-Application
discontinued	O
the	O
OpenSolaris	B-Operating_System
download	O
sites	O
after	O
its	O
acquisition	O
of	O
Sun	O
Microsystems	O
,	O
but	O
source	O
code	O
for	O
Crossbow	O
can	O
be	O
downloaded	O
from	O
the	O
sites	O
of	O
the	O
derivatives	O
of	O
illumos	B-Application
(	O
see	O
)	O
.	O
</s>
