<s>
In	O
computer	B-Architecture
networking	I-Architecture
,	O
link	B-Architecture
aggregation	I-Architecture
is	O
the	O
combining	O
(	O
aggregating	O
)	O
of	O
multiple	O
network	O
connections	O
in	O
parallel	O
by	O
any	O
of	O
several	O
methods	O
.	O
</s>
<s>
Link	B-Architecture
aggregation	I-Architecture
increases	O
total	O
throughput	O
beyond	O
what	O
a	O
single	O
connection	O
could	O
sustain	O
,	O
and	O
provides	O
redundancy	O
where	O
all	O
but	O
one	O
of	O
the	O
physical	B-Application
links	I-Application
may	O
fail	O
without	O
losing	O
connectivity	O
.	O
</s>
<s>
A	O
link	B-Architecture
aggregation	I-Architecture
group	I-Architecture
(	O
LAG	O
)	O
is	O
the	O
combined	O
collection	O
of	O
physical	O
ports	O
.	O
</s>
<s>
Other	O
umbrella	O
terms	O
used	O
to	O
describe	O
the	O
concept	O
include	O
trunking	O
,	O
bundling	O
,	O
bonding	B-Architecture
,	O
channeling	O
or	O
teaming	B-Architecture
.	O
</s>
<s>
Implementation	O
may	O
follow	O
vendor-independent	O
standards	O
such	O
as	O
Link	B-Architecture
Aggregation	I-Architecture
Control	O
Protocol	O
(	O
LACP	O
)	O
for	O
Ethernet	O
,	O
defined	O
in	O
IEEE	O
802.1AX	O
or	O
the	O
previous	O
IEEE	O
802.3ad	O
,	O
but	O
also	O
proprietary	O
protocols	O
.	O
</s>
<s>
Link	B-Architecture
aggregation	I-Architecture
increases	O
the	O
bandwidth	O
and	O
resilience	O
of	O
Ethernet	O
connections	O
.	O
</s>
<s>
An	O
alternative	O
solution	O
,	O
introduced	O
by	O
many	O
of	O
the	O
network	O
manufacturers	O
in	O
the	O
early	O
1990s	O
,	O
is	O
to	O
use	O
link	B-Architecture
aggregation	I-Architecture
to	O
combine	O
two	O
physical	O
Ethernet	O
links	O
into	O
one	O
logical	O
link	O
.	O
</s>
<s>
There	O
are	O
three	O
single	B-Architecture
points	I-Architecture
of	I-Architecture
failure	I-Architecture
inherent	O
to	O
a	O
typical	O
port-cable-port	O
connection	O
,	O
in	O
either	O
a	O
computer-to-switch	O
or	O
a	O
switch-to-switch	O
configuration	O
:	O
the	O
cable	O
itself	O
or	O
either	O
of	O
the	O
ports	O
the	O
cable	O
is	O
plugged	O
into	O
can	O
fail	O
.	O
</s>
<s>
Multiple	O
logical	O
connections	O
can	O
be	O
made	O
,	O
but	O
many	O
of	O
the	O
higher	O
level	O
protocols	O
were	O
not	O
designed	O
to	O
fail	B-General_Concept
over	I-General_Concept
completely	O
seamlessly	O
.	O
</s>
<s>
Combining	O
multiple	O
physical	O
connections	O
into	O
one	O
logical	O
connection	O
using	O
link	B-Architecture
aggregation	I-Architecture
provides	O
more	O
resilient	O
communications	O
.	O
</s>
<s>
Network	B-Architecture
architects	I-Architecture
can	O
implement	O
aggregation	O
at	O
any	O
of	O
the	O
lowest	O
three	O
layers	O
of	O
the	O
OSI	O
model	O
.	O
</s>
<s>
Examples	O
of	O
aggregation	O
at	O
layer	B-Application
1	I-Application
(	O
physical	B-Application
layer	I-Application
)	O
include	O
power	B-Device
line	I-Device
(	O
e.g.	O
</s>
<s>
IEEE	O
1901	O
)	O
and	O
wireless	B-Architecture
(	O
e.g.	O
</s>
<s>
OSI	B-Protocol
layer	I-Protocol
2	I-Protocol
(	O
data	B-Protocol
link	I-Protocol
layer	I-Protocol
,	O
e.g.	O
</s>
<s>
Ethernet	B-Protocol
frame	I-Protocol
in	O
LANs	O
or	O
multi-link	O
PPP	O
in	O
WANs	O
,	O
Ethernet	O
MAC	O
address	O
)	O
aggregation	O
typically	O
occurs	O
across	O
switch	B-Protocol
ports	I-Protocol
,	O
which	O
can	O
be	O
either	O
physical	O
ports	O
or	O
virtual	O
ones	O
managed	O
by	O
an	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Aggregation	O
at	O
layer	B-Application
3	I-Application
(	O
network	B-Application
layer	I-Application
)	O
in	O
the	O
OSI	O
model	O
can	O
use	O
round-robin	O
scheduling	O
,	O
hash	O
values	O
computed	O
from	O
fields	O
in	O
the	O
packet	B-Protocol
header	O
,	O
or	O
a	O
combination	O
of	O
these	O
two	O
methods	O
.	O
</s>
<s>
However	O
,	O
in	O
order	O
to	O
avoid	O
out-of-order	B-Protocol
delivery	I-Protocol
,	O
not	O
all	O
implementations	O
take	O
advantage	O
of	O
this	O
.	O
</s>
<s>
Most	O
methods	O
provide	O
failover	B-General_Concept
as	O
well	O
.	O
</s>
<s>
Channel	B-Architecture
bonding	I-Architecture
is	O
differentiated	O
from	O
load	B-Application
balancing	I-Application
in	O
that	O
load	B-Application
balancing	I-Application
divides	O
traffic	O
between	O
network	O
interfaces	O
on	O
per	O
network	B-Protocol
socket	I-Protocol
(	O
layer	B-Architecture
4	I-Architecture
)	O
basis	O
,	O
while	O
channel	B-Architecture
bonding	I-Architecture
implies	O
a	O
division	O
of	O
traffic	O
between	O
physical	O
interfaces	O
at	O
a	O
lower	O
level	O
,	O
either	O
per	O
packet	B-Protocol
(	O
layer	B-Application
3	I-Application
)	O
or	O
a	O
data	O
link	O
(	O
layer	B-Protocol
2	I-Protocol
)	O
basis	O
.	O
</s>
<s>
By	O
the	O
mid-1990s	O
,	O
most	O
network	B-Protocol
switch	I-Protocol
manufacturers	O
had	O
included	O
aggregation	O
capability	O
as	O
a	O
proprietary	O
extension	O
to	O
increase	O
bandwidth	O
between	O
their	O
switches	O
.	O
</s>
<s>
The	O
IEEE	O
802.3	O
working	O
group	O
took	O
up	O
a	O
study	O
group	O
to	O
create	O
an	O
interoperable	O
link	B-Protocol
layer	I-Protocol
standard	O
(	O
i.e.	O
</s>
<s>
encompassing	O
the	O
physical	O
and	O
data-link	B-Protocol
layers	I-Protocol
both	O
)	O
in	O
a	O
November	O
1997	O
meeting	O
.	O
</s>
<s>
This	O
became	O
known	O
as	O
Link	B-Architecture
Aggregation	I-Architecture
Control	O
Protocol	O
(	O
LACP	O
)	O
.	O
</s>
<s>
,	O
most	O
gigabit	O
channel-bonding	O
schemes	O
used	O
the	O
IEEE	O
standard	O
of	O
link	B-Architecture
aggregation	I-Architecture
which	O
was	O
formerly	O
clause	O
43	O
of	O
the	O
IEEE	O
802.3	O
standard	O
added	O
in	O
March	O
2000	O
by	O
the	O
IEEE	O
802.3ad	O
task	O
force	O
.	O
</s>
<s>
The	O
802.3	O
maintenance	O
task	O
force	O
report	O
for	O
the	O
9th	O
revision	O
project	O
in	O
November	O
2006	O
noted	O
that	O
certain	O
802.1	O
layers	O
(	O
such	O
as	O
802.1X	O
security	O
)	O
were	O
positioned	O
in	O
the	O
protocol	B-Protocol
stack	I-Protocol
below	O
link	B-Architecture
aggregation	I-Architecture
which	O
was	O
defined	O
as	O
an	O
802.3	O
sublayer	O
.	O
</s>
<s>
Within	O
the	O
IEEE	O
Ethernet	O
standards	O
,	O
the	O
Link	B-Architecture
Aggregation	I-Architecture
Control	O
Protocol	O
(	O
LACP	O
)	O
provides	O
a	O
method	O
to	O
control	O
the	O
bundling	O
of	O
several	O
physical	B-Application
links	I-Application
together	O
to	O
form	O
a	O
single	O
logical	O
link	O
.	O
</s>
<s>
LACP	O
allows	O
a	O
network	O
device	O
to	O
negotiate	O
an	O
automatic	O
bundling	O
of	O
links	O
by	O
sending	O
LACP	O
packets	B-Protocol
to	O
their	O
peer	O
,	O
a	O
directly	O
connected	O
device	O
that	O
also	O
implements	O
LACP	O
.	O
</s>
<s>
Maximum	O
number	O
of	O
bundled	O
ports	O
allowed	O
in	O
the	O
port	B-Architecture
channel	I-Architecture
:	O
Valid	O
values	O
are	O
usually	O
from	O
1	O
to	O
8	O
.	O
</s>
<s>
Failover	B-General_Concept
occurs	O
automatically	O
:	O
When	O
a	O
link	O
has	O
an	O
intermediate	O
failure	O
,	O
for	O
example	O
in	O
a	O
media	B-Protocol
converter	I-Protocol
between	O
the	O
devices	O
,	O
a	O
peer	O
system	O
may	O
not	O
perceive	O
any	O
connectivity	O
problems	O
.	O
</s>
<s>
With	O
static	O
link	B-Architecture
aggregation	I-Architecture
,	O
the	O
peer	O
would	O
continue	O
sending	O
traffic	O
down	O
the	O
link	O
causing	O
the	O
connection	O
to	O
fail	O
.	O
</s>
<s>
Dynamic	O
configuration	O
:	O
The	O
device	O
can	O
confirm	O
that	O
the	O
configuration	O
at	O
the	O
other	O
end	O
can	O
handle	O
link	B-Architecture
aggregation	I-Architecture
.	O
</s>
<s>
With	O
static	O
link	B-Architecture
aggregation	I-Architecture
,	O
a	O
cabling	O
or	O
configuration	O
mistake	O
could	O
go	O
undetected	O
and	O
cause	O
undesirable	O
network	O
behavior	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
IEEE	O
link	B-Architecture
aggregation	I-Architecture
substandards	O
,	O
there	O
are	O
a	O
number	O
of	O
proprietary	O
aggregation	O
schemes	O
including	O
Cisco	O
's	O
EtherChannel	B-Protocol
and	O
Port	B-Protocol
Aggregation	I-Protocol
Protocol	I-Protocol
,	O
Juniper	O
's	O
Aggregated	O
Ethernet	O
,	O
AVAYA	O
's	O
Multi-Link	B-Protocol
Trunking	I-Protocol
,	O
Split	O
Multi-Link	B-Protocol
Trunking	I-Protocol
,	O
Routed	O
Split	O
Multi-Link	B-Protocol
Trunking	I-Protocol
and	O
Distributed	O
Split	O
Multi-Link	B-Protocol
Trunking	I-Protocol
,	O
ZTE	O
's	O
Smartgroup	O
,	O
Huawei	O
's	O
Eth-Trunk	O
,	O
and	O
Connectify	B-Protocol
's	O
Speedify	O
.	O
</s>
<s>
Most	O
high-end	O
network	O
devices	O
support	O
some	O
form	O
of	O
link	B-Architecture
aggregation	I-Architecture
.	O
</s>
<s>
Software-based	O
implementations	O
–	O
such	O
as	O
the	O
*	B-Operating_System
BSD	I-Operating_System
lagg	O
package	O
,	O
Linux	B-Application
bonding	B-Architecture
driver	O
,	O
Solaris	B-Application
dladm	O
aggr	O
,	O
etc	O
.	O
</s>
<s>
–	O
exist	O
for	O
many	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
The	O
Linux	B-Application
bonding	B-Architecture
driver	O
provides	O
a	O
method	O
for	O
aggregating	O
multiple	O
network	B-Protocol
interface	I-Protocol
controllers	I-Protocol
(	O
NICs	O
)	O
into	O
a	O
single	O
logical	O
bonded	O
interface	O
of	O
two	O
or	O
more	O
so-called	O
(	O
NIC	B-Protocol
)	O
slaves	O
.	O
</s>
<s>
The	O
majority	O
of	O
modern	O
Linux	B-Application
distributions	I-Application
come	O
with	O
a	O
Linux	B-Operating_System
kernel	I-Operating_System
which	O
has	O
the	O
Linux	B-Application
bonding	B-Architecture
driver	O
integrated	O
as	O
a	O
loadable	B-Application
kernel	I-Application
module	I-Application
and	O
the	O
ifenslave	O
(	O
if	O
=	O
 [ network ] 	O
interface	O
)	O
user-level	B-Operating_System
control	O
program	O
pre-installed	O
.	O
</s>
<s>
Donald	O
Becker	O
programmed	O
the	O
original	O
Linux	B-Application
bonding	B-Architecture
driver	O
.	O
</s>
<s>
It	O
came	O
into	O
use	O
with	O
the	O
Beowulf	B-Operating_System
cluster	I-Operating_System
patches	O
for	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
2.0	I-Operating_System
.	O
</s>
<s>
Modes	O
for	O
the	O
Linux	B-Application
bonding	B-Architecture
driver	O
(	O
network	O
interface	O
aggregation	O
modes	O
)	O
are	O
supplied	O
as	O
parameters	O
to	O
the	O
kernel	B-Operating_System
bonding	B-Architecture
module	B-Application
at	O
load	O
time	O
.	O
</s>
<s>
The	O
behavior	O
of	O
the	O
single	O
logical	O
bonded	O
interface	O
depends	O
upon	O
its	O
specified	O
bonding	B-Architecture
driver	O
mode	O
.	O
</s>
<s>
Round-robin	O
(	O
balance-rr	O
)	O
Transmit	O
alternate	O
network	B-Protocol
packets	I-Protocol
in	O
sequential	O
order	O
from	O
the	O
first	O
available	O
NIC	B-Protocol
slave	O
through	O
the	O
last	O
.	O
</s>
<s>
This	O
mode	O
provides	O
load	B-Application
balancing	I-Application
and	O
fault	B-General_Concept
tolerance	I-General_Concept
.	O
</s>
<s>
This	O
mode	O
can	O
cause	O
congestion	O
control	O
issues	O
due	O
to	O
the	O
packet	B-Protocol
reordering	I-Protocol
it	O
can	O
introduce	O
.	O
</s>
<s>
Active-backup	O
(	O
active-backup	O
)	O
Only	O
one	O
NIC	B-Protocol
slave	O
in	O
the	O
bond	O
is	O
active	O
.	O
</s>
<s>
The	O
single	O
logical	O
bonded	O
interface	O
's	O
MAC	O
address	O
is	O
externally	O
visible	O
on	O
only	O
one	O
NIC	B-Protocol
(	O
port	O
)	O
to	O
simplify	O
forwarding	O
in	O
the	O
network	B-Protocol
switch	I-Protocol
.	O
</s>
<s>
This	O
mode	O
provides	O
fault	B-General_Concept
tolerance	I-General_Concept
.	O
</s>
<s>
XOR	O
(	O
balance-xor	O
)	O
Transmit	O
network	B-Protocol
packets	I-Protocol
based	O
on	O
a	O
hash	O
of	O
the	O
packet	B-Protocol
's	O
source	O
and	O
destination	O
.	O
</s>
<s>
This	O
selects	O
the	O
same	O
NIC	B-Protocol
slave	O
for	O
each	O
destination	O
MAC	O
address	O
,	O
IP	O
address	O
,	O
or	O
IP	O
address	O
and	O
port	O
combination	O
,	O
respectively	O
.	O
</s>
<s>
Single	O
connections	O
will	O
have	O
guaranteed	O
in	O
order	O
packet	B-Protocol
delivery	O
and	O
will	O
transmit	O
at	O
the	O
speed	O
of	O
a	O
single	O
NIC	B-Protocol
.	O
</s>
<s>
This	O
mode	O
provides	O
load	B-Application
balancing	I-Application
and	O
fault	B-General_Concept
tolerance	I-General_Concept
.	O
</s>
<s>
Broadcast	O
(	O
broadcast	O
)	O
Transmit	O
network	B-Protocol
packets	I-Protocol
on	O
all	O
slave	O
network	O
interfaces	O
.	O
</s>
<s>
This	O
mode	O
provides	O
fault	B-General_Concept
tolerance	I-General_Concept
.	O
</s>
<s>
IEEE	O
802.3ad	O
Dynamic	O
link	B-Architecture
aggregation	I-Architecture
(	O
802.3ad	O
,	O
LACP	O
)	O
Creates	O
aggregation	O
groups	O
that	O
share	O
the	O
same	O
speed	O
and	O
duplex	O
settings	O
.	O
</s>
<s>
Adaptive	O
transmit	O
load	B-Application
balancing	I-Application
(	O
balance-tlb	O
)	O
Linux	B-Application
bonding	B-Architecture
driver	O
mode	O
that	O
does	O
not	O
require	O
any	O
special	O
network-switch	O
support	O
.	O
</s>
<s>
The	O
outgoing	O
network	B-Protocol
packet	I-Protocol
traffic	O
is	O
distributed	O
according	O
to	O
the	O
current	O
load	O
(	O
computed	O
relative	O
to	O
the	O
speed	O
)	O
on	O
each	O
network	O
interface	O
slave	O
.	O
</s>
<s>
Adaptive	O
load	B-Application
balancing	I-Application
(	O
balance-alb	O
)	O
includes	O
balance-tlb	O
plus	O
receive	O
load	B-Application
balancing	I-Application
(	O
rlb	O
)	O
for	O
IPv4	O
traffic	O
and	O
does	O
not	O
require	O
any	O
special	O
network	B-Protocol
switch	I-Protocol
support	O
.	O
</s>
<s>
The	O
receive	O
load	B-Application
balancing	I-Application
is	O
achieved	O
by	O
ARP	O
negotiation	O
.	O
</s>
<s>
The	O
bonding	B-Architecture
driver	O
intercepts	O
the	O
ARP	O
Replies	O
sent	O
by	O
the	O
local	O
system	O
on	O
their	O
way	O
out	O
and	O
overwrites	O
the	O
source	O
hardware	O
address	O
with	O
the	O
unique	O
hardware	O
address	O
of	O
one	O
of	O
the	O
NIC	B-Protocol
slaves	O
in	O
the	O
single	O
logical	O
bonded	O
interface	O
such	O
that	O
different	O
network-peers	O
use	O
different	O
MAC	O
addresses	O
for	O
their	O
network	B-Protocol
packet	I-Protocol
traffic	O
.	O
</s>
<s>
The	O
Linux	B-Application
Team	O
driver	O
provides	O
an	O
alternative	O
to	O
bonding	B-Architecture
driver	O
.	O
</s>
<s>
The	O
main	O
difference	O
is	O
that	O
Team	O
driver	O
kernel	B-Operating_System
part	O
contains	O
only	O
essential	O
code	O
and	O
the	O
rest	O
of	O
the	O
code	O
(	O
link	O
validation	O
,	O
LACP	O
implementation	O
,	O
decision	O
making	O
,	O
etc	O
.	O
)	O
</s>
<s>
is	O
run	O
in	O
userspace	B-Operating_System
as	O
a	O
part	O
of	O
teamd	O
daemon	O
.	O
</s>
<s>
Link	B-Architecture
aggregation	I-Architecture
offers	O
an	O
inexpensive	O
way	O
to	O
set	O
up	O
a	O
high-capacity	O
backbone	B-General_Concept
network	I-General_Concept
that	O
transfers	O
multiple	O
times	O
more	O
data	O
than	O
any	O
single	O
port	O
or	O
device	O
can	O
deliver	O
.	O
</s>
<s>
Link	B-Architecture
aggregation	I-Architecture
also	O
allows	O
the	O
network	O
's	O
backbone	O
speed	O
to	O
grow	O
incrementally	O
as	O
demand	O
on	O
the	O
network	O
increases	O
,	O
without	O
having	O
to	O
replace	O
everything	O
and	O
deploy	O
new	O
hardware	O
.	O
</s>
<s>
Link	B-Architecture
aggregation	I-Architecture
can	O
allow	O
the	O
use	O
of	O
these	O
extra	O
cables	O
to	O
increase	O
backbone	O
speeds	O
for	O
little	O
or	O
no	O
extra	O
cost	O
if	O
ports	O
are	O
available	O
.	O
</s>
<s>
When	O
balancing	O
traffic	O
,	O
network	O
administrators	O
often	O
wish	O
to	O
avoid	O
reordering	O
Ethernet	B-Protocol
frames	I-Protocol
.	O
</s>
<s>
For	O
example	O
,	O
TCP	O
suffers	O
additional	O
overhead	O
when	O
dealing	O
with	O
out-of-order	O
packets	B-Protocol
.	O
</s>
<s>
based	O
on	O
the	O
MAC	O
or	O
the	O
IP	O
addresses	O
)	O
,	O
ensuring	O
that	O
the	O
same	O
flow	O
is	O
always	O
sent	O
via	O
the	O
same	O
physical	B-Application
link	I-Application
.	O
</s>
<s>
For	O
this	O
reason	O
,	O
an	O
even	O
load	B-Application
balancing	I-Application
and	O
full	O
utilization	O
of	O
all	O
trunked	O
links	O
is	O
almost	O
never	O
reached	O
in	O
real-life	O
implementations	O
.	O
</s>
<s>
NICs	O
trunked	O
together	O
can	O
also	O
provide	O
network	O
links	O
beyond	O
the	O
throughput	O
of	O
any	O
one	O
single	O
NIC	B-Protocol
.	O
</s>
<s>
Note	O
the	O
data	O
signaling	O
rate	O
will	O
still	O
be	O
1Gbit/s	O
,	O
which	O
can	O
be	O
misleading	O
depending	O
on	O
methodologies	O
used	O
to	O
test	O
throughput	O
after	O
link	B-Architecture
aggregation	I-Architecture
is	O
employed	O
.	O
</s>
<s>
Microsoft	B-Application
Windows	I-Application
Server	O
2012	O
supports	O
link	B-Architecture
aggregation	I-Architecture
natively	O
.	O
</s>
<s>
Previous	O
Windows	O
Server	O
versions	O
relied	O
on	O
manufacturer	O
support	O
of	O
the	O
feature	O
within	O
their	O
device	B-Application
driver	I-Application
software	O
.	O
</s>
<s>
Nvidia	O
supports	O
teaming	B-Architecture
with	O
their	O
Nvidia	O
Network	O
Access	O
Manager/Firewall	O
Tool	O
.	O
</s>
<s>
HP	O
has	O
a	O
teaming	B-Architecture
tool	O
for	O
HP-branded	O
NICs	O
which	O
supports	O
several	O
modes	O
of	O
link	B-Architecture
aggregation	I-Architecture
including	O
802.3ad	O
with	O
LACP	O
.	O
</s>
<s>
In	O
addition	O
,	O
there	O
is	O
a	O
basic	O
layer-3	B-Application
aggregation	O
that	O
allows	O
servers	O
with	O
multiple	O
IP	O
interfaces	O
on	O
the	O
same	O
network	O
to	O
perform	O
load	B-Application
balancing	I-Application
,	O
and	O
for	O
home	O
users	O
with	O
more	O
than	O
one	O
internet	O
connection	O
,	O
to	O
increase	O
connection	O
speed	O
by	O
sharing	O
the	O
load	O
on	O
all	O
interfaces	O
.	O
</s>
<s>
Broadcom	O
offers	O
advanced	O
functions	O
via	O
Broadcom	O
Advanced	O
Control	O
Suite	O
(	O
BACS	O
)	O
,	O
via	O
which	O
the	O
teaming	B-Architecture
functionality	O
of	O
BASP	O
(	O
Broadcom	O
Advanced	O
Server	O
Program	O
)	O
is	O
available	O
,	O
offering	O
802.3ad	O
static	O
LAGs	O
,	O
LACP	O
,	O
and	O
"	O
smart	O
teaming	B-Architecture
"	O
which	O
does	O
n't	O
require	O
any	O
configuration	O
on	O
the	O
switches	O
to	O
work	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
configure	O
teaming	B-Architecture
with	O
BACS	O
with	O
a	O
mix	O
of	O
NICs	O
from	O
different	O
vendors	O
as	O
long	O
as	O
at	O
least	O
one	O
of	O
them	O
is	O
from	O
Broadcom	O
and	O
the	O
other	O
NICs	O
have	O
the	O
required	O
capabilities	O
to	O
support	O
teaming	B-Architecture
.	O
</s>
<s>
Linux	B-Application
,	O
FreeBSD	B-Operating_System
,	O
NetBSD	B-Device
,	O
OpenBSD	B-Operating_System
,	O
macOS	B-Application
,	O
OpenSolaris	B-Operating_System
and	O
commercial	O
Unix	O
distributions	O
such	O
as	O
AIX	B-Application
implement	O
Ethernet	B-Architecture
bonding	I-Architecture
at	O
a	O
higher	O
level	O
and	O
,	O
as	O
long	O
as	O
the	O
NIC	B-Protocol
is	O
supported	O
by	O
the	O
kernel	B-Operating_System
,	O
can	O
deal	O
with	O
NICs	O
from	O
different	O
manufacturers	O
or	O
using	O
different	O
drivers	O
.	O
</s>
<s>
Citrix	B-Operating_System
XenServer	I-Operating_System
and	O
VMware	B-Operating_System
ESX	I-Operating_System
have	O
native	O
support	O
for	O
link	B-Architecture
aggregation	I-Architecture
.	O
</s>
<s>
XenServer	B-Operating_System
offers	O
both	O
static	O
LAGs	O
as	O
well	O
as	O
LACP	O
.	O
</s>
<s>
vSphere	O
5.1	O
(	O
ESXi	B-Operating_System
)	O
supports	O
both	O
static	O
LAGs	O
and	O
LACP	O
natively	O
with	O
their	O
virtual	O
distributed	O
switch	B-Protocol
.	O
</s>
<s>
Microsoft	O
's	O
Hyper-V	O
does	O
not	O
offer	O
link	B-Architecture
aggregation	I-Architecture
support	O
from	O
the	O
hypervisor	O
level	O
,	O
but	O
the	O
above-mentioned	O
methods	O
for	O
teaming	B-Architecture
under	O
Windows	O
apply	O
to	O
Hyper-V	O
.	O
</s>
<s>
With	O
the	O
modes	O
balance-rr	O
,	O
balance-xor	O
,	O
broadcast	O
and	O
802.3ad	O
,	O
all	O
physical	O
ports	O
in	O
the	O
link	B-Architecture
aggregation	I-Architecture
group	I-Architecture
must	O
reside	O
on	O
the	O
same	O
logical	O
switch	B-Protocol
,	O
which	O
,	O
in	O
most	O
common	O
scenarios	O
,	O
will	O
leave	O
a	O
single	B-Architecture
point	I-Architecture
of	I-Architecture
failure	I-Architecture
when	O
the	O
physical	O
switch	B-Protocol
to	O
which	O
all	O
links	O
are	O
connected	O
goes	O
offline	O
.	O
</s>
<s>
But	O
after	O
failover	B-General_Concept
(	O
like	O
all	O
other	O
modes	O
)	O
,	O
in	O
some	O
cases	O
,	O
active	O
sessions	O
may	O
fail	O
(	O
due	O
to	O
ARP	O
problems	O
)	O
and	O
have	O
to	O
be	O
restarted	O
.	O
</s>
<s>
However	O
,	O
almost	O
all	O
vendors	O
have	O
proprietary	O
extensions	O
that	O
resolve	O
some	O
of	O
this	O
issue	O
:	O
they	O
aggregate	O
multiple	O
physical	O
switches	O
into	O
one	O
logical	O
switch	B-Protocol
.	O
</s>
<s>
Notel	O
's	O
split	O
multi-link	B-Protocol
trunking	I-Protocol
(	O
SMLT	O
)	O
protocol	O
allows	O
multiple	O
Ethernet	O
links	O
to	O
be	O
split	O
across	O
multiple	O
switches	O
in	O
a	O
stack	O
,	O
preventing	O
any	O
single	B-Architecture
point	I-Architecture
of	I-Architecture
failure	I-Architecture
and	O
additionally	O
allowing	O
all	O
switches	O
to	O
be	O
load	O
balanced	O
across	O
multiple	O
aggregation	O
switches	O
from	O
the	O
single	O
access	O
stack	O
.	O
</s>
<s>
These	O
devices	O
synchronize	O
state	O
across	O
an	O
Inter-Switch	B-Protocol
Trunk	I-Protocol
(	O
IST	O
)	O
such	O
that	O
they	O
appear	O
to	O
the	O
connecting	O
(	O
access	O
)	O
device	O
to	O
be	O
a	O
single	O
device	O
(	O
switch	B-Protocol
block	O
)	O
and	O
prevent	O
any	O
packet	B-Protocol
duplication	O
.	O
</s>
<s>
SMLT	O
provides	O
enhanced	O
resiliency	O
with	O
sub-second	O
failover	B-General_Concept
and	O
sub-second	O
recovery	O
for	O
all	O
speed	O
trunks	O
while	O
operating	O
transparently	O
to	O
end-devices	O
.	O
</s>
<s>
Multi-chassis	B-Protocol
link	I-Protocol
aggregation	I-Protocol
group	I-Protocol
provides	O
similar	O
features	O
in	O
a	O
vendor-nonspecific	O
manner	O
.	O
</s>
<s>
Many	O
switches	O
are	O
PHY	O
independent	O
,	O
meaning	O
that	O
a	O
switch	B-Protocol
could	O
have	O
a	O
mixture	O
of	O
copper	O
,	O
SX	O
,	O
LX	O
,	O
LX10	O
or	O
other	O
GBIC/SFP	O
modular	O
transceivers	O
.	O
</s>
<s>
One	O
path	O
may	O
have	O
a	O
slightly	O
longer	O
propagation	O
time	O
but	O
since	O
most	O
implementations	O
keep	O
a	O
single	O
traffic	O
flow	O
on	O
the	O
same	O
physical	B-Application
link	I-Application
(	O
using	O
a	O
hash	O
of	O
either	O
MAC	O
addresses	O
,	O
IP	O
addresses	O
,	O
or	O
IP/transport	O
-layer	O
port	O
combinations	O
as	O
index	O
)	O
that	O
is	O
n't	O
an	O
issue	O
usually	O
.	O
</s>
<s>
Some	O
switches	O
do	O
not	O
implement	O
the	O
802.1AX	O
standard	O
but	O
support	O
static	O
configuration	O
of	O
link	B-Architecture
aggregation	I-Architecture
.	O
</s>
<s>
Therefore	O
,	O
link	B-Architecture
aggregation	I-Architecture
between	O
similarly	O
statically	O
configured	O
switches	O
will	O
work	O
but	O
will	O
fail	O
between	O
a	O
statically	O
configured	O
switch	B-Protocol
and	O
a	O
device	O
that	O
is	O
configured	O
for	O
LACP	O
.	O
</s>
<s>
On	O
Ethernet	O
interfaces	O
,	O
channel	B-Architecture
bonding	I-Architecture
requires	O
assistance	O
from	O
both	O
the	O
Ethernet	B-Protocol
switch	I-Protocol
and	O
the	O
host	O
computer	O
's	O
operating	B-General_Concept
system	I-General_Concept
,	O
which	O
must	O
"	B-Protocol
stripe	I-Protocol
"	I-Protocol
the	I-Protocol
delivery	I-Protocol
of	O
frames	O
across	O
the	O
network	O
interfaces	O
in	O
the	O
same	O
manner	O
that	O
I/O	O
is	O
striped	O
across	O
disks	O
in	O
a	O
RAID	B-Architecture
0	I-Architecture
array	O
.	O
</s>
<s>
For	O
this	O
reason	O
,	O
some	O
discussions	O
of	O
channel	B-Architecture
bonding	I-Architecture
also	O
refer	O
to	O
Redundant	O
Array	O
of	O
Inexpensive	O
Nodes	O
(	O
RAIN	O
)	O
or	O
to	O
"	O
redundant	O
array	O
of	O
independent	O
network	O
interfaces	O
"	O
.	O
</s>
<s>
Broadband	O
bonding	B-Architecture
is	O
a	O
type	O
of	O
channel	B-Architecture
bonding	I-Architecture
that	O
refers	O
to	O
aggregation	O
of	O
multiple	O
channels	O
at	O
OSI	O
layers	O
at	O
level	O
four	O
or	O
above	O
.	O
</s>
<s>
Additionally	O
,	O
it	O
is	O
possible	O
to	O
bond	O
multiple	O
cellular	O
links	O
for	O
an	O
aggregated	O
wireless	B-Architecture
bonded	O
link	O
.	O
</s>
<s>
Previous	O
bonding	B-Architecture
methodologies	O
resided	O
at	O
lower	O
OSI	O
layers	O
,	O
requiring	O
coordination	O
with	O
telecommunications	O
companies	O
for	O
implementation	O
.	O
</s>
<s>
Broadband	O
bonding	B-Architecture
,	O
because	O
it	O
is	O
implemented	O
at	O
higher	O
layers	O
,	O
can	O
be	O
done	O
without	O
this	O
coordination	O
.	O
</s>
<s>
Commercial	O
implementations	O
of	O
Broadband	O
Channel	B-Architecture
Bonding	I-Architecture
include	O
:	O
</s>
<s>
On	O
802.11	O
(	O
Wi-Fi	O
)	O
,	O
channel	B-Architecture
bonding	I-Architecture
is	O
used	O
in	O
Super	B-Device
G	I-Device
technology	O
,	O
referred	O
to	O
as	O
108Mbit/s	O
.	O
</s>
<s>
This	O
is	O
not	O
channel	B-Architecture
bonding	I-Architecture
,	O
but	O
a	O
single	O
channel	O
with	O
double	O
the	O
older	O
20MHz	O
channel	O
width	O
,	O
thus	O
using	O
two	O
adjacent	O
20MHz	O
bands	O
.	O
</s>
<s>
This	O
allows	O
direct	O
doubling	O
of	O
the	O
PHY	O
data	O
rate	O
from	O
a	O
single	O
20MHz	O
channel	O
,	O
but	O
the	O
MAC	O
and	O
user-level	B-Operating_System
throughput	O
also	O
depends	O
on	O
other	O
factors	O
so	O
may	O
not	O
double	O
.	O
</s>
