<s>
Flex	B-General_Concept
links	I-General_Concept
is	O
a	O
network	B-Protocol
switch	I-Protocol
feature	O
in	O
Cisco	O
equipment	O
which	O
enables	O
redundancy	O
and	O
load	B-Application
balancing	I-Application
at	O
the	O
layer	B-Protocol
2	I-Protocol
level	O
.	O
</s>
<s>
The	O
feature	O
serves	O
as	O
an	O
alternative	O
to	O
Spanning	B-Protocol
Tree	I-Protocol
Protocol	I-Protocol
or	O
link	B-Architecture
aggregation	I-Architecture
.	O
</s>
<s>
A	O
pair	O
of	O
layer	B-Protocol
2	I-Protocol
interfaces	O
,	O
such	O
as	O
switch	B-Protocol
ports	I-Protocol
or	O
port	B-Architecture
channels	I-Architecture
,	O
has	O
one	O
interface	O
configured	O
as	O
a	O
backup	O
to	O
the	O
other	O
.	O
</s>
<s>
Load	B-Application
balancing	I-Application
in	O
Flex	B-General_Concept
links	I-General_Concept
work	O
at	O
VLAN	B-General_Concept
level	O
.	O
</s>
<s>
One	O
port	O
in	O
the	O
flex	B-General_Concept
links	I-General_Concept
pair	O
can	O
be	O
configured	O
to	O
forward	O
traffic	O
belonging	O
to	O
VLANs	B-General_Concept
1-50	O
and	O
the	O
other	O
can	O
forward	O
traffic	O
for	O
VLANs	B-General_Concept
51-100	O
.	O
</s>
<s>
Mutually	O
exclusive	O
VLANs	B-General_Concept
are	O
load	B-Application
sharing	I-Application
the	O
traffic	O
between	O
the	O
Flex	O
link	O
pairs	O
.	O
</s>
