<s>
Virtual	B-Protocol
Extensible	I-Protocol
LAN	I-Protocol
(	O
VXLAN	B-Protocol
)	O
is	O
a	O
network	B-Protocol
virtualization	I-Protocol
technology	O
that	O
attempts	O
to	O
address	O
the	O
scalability	B-Architecture
problems	O
associated	O
with	O
large	O
cloud	B-Architecture
computing	I-Architecture
deployments	O
.	O
</s>
<s>
It	O
uses	O
a	O
VLAN-like	O
encapsulation	O
technique	O
to	O
encapsulate	O
OSI	B-Protocol
layer	I-Protocol
2	I-Protocol
Ethernet	B-Protocol
frames	I-Protocol
within	O
layer	B-Architecture
4	I-Architecture
UDP	B-Protocol
datagrams	O
,	O
using	O
4789	O
as	O
the	O
default	O
IANA-assigned	O
destination	O
UDP	B-Protocol
port	O
number	O
.	O
</s>
<s>
VXLAN	B-Protocol
endpoints	O
,	O
which	O
terminate	O
VXLAN	B-Protocol
tunnels	O
and	O
may	O
be	O
either	O
virtual	O
or	O
physical	O
switch	B-Protocol
ports	I-Protocol
,	O
are	O
known	O
as	O
VXLAN	B-Protocol
tunnel	I-Protocol
endpoints	I-Protocol
(	O
VTEPs	B-Protocol
)	O
.	O
</s>
<s>
VXLAN	B-Protocol
is	O
an	O
evolution	O
of	O
efforts	O
to	O
standardize	O
on	O
an	O
overlay	O
encapsulation	O
protocol	O
.	O
</s>
<s>
Compared	O
to	O
VLAN	B-General_Concept
which	O
provides	O
limited	O
number	O
of	O
layer-2	B-Protocol
VLANs	B-General_Concept
(	O
typically	O
using	O
12-bit	O
VLAN	B-General_Concept
ID	O
)	O
,	O
VXLAN	B-Protocol
increases	O
scalability	B-Architecture
up	O
to	O
16	O
million	O
logical	O
networks	O
(	O
with	O
24-bit	O
VNID	O
)	O
and	O
allows	O
for	O
layer-2	B-Protocol
adjacency	O
across	O
IP	O
networks	O
.	O
</s>
<s>
Multicast	O
or	O
unicast	B-Protocol
with	O
head-end	O
replication	O
(	O
HER	O
)	O
is	O
used	O
to	O
flood	O
Broadcast	B-Protocol
,	I-Protocol
unknown-unicast	I-Protocol
and	I-Protocol
multicast	I-Protocol
traffic	I-Protocol
.	O
</s>
<s>
The	O
VXLAN	B-Protocol
specification	O
was	O
originally	O
created	O
by	O
VMware	O
,	O
Arista	O
Networks	O
and	O
Cisco	O
.	O
</s>
<s>
Other	O
backers	O
of	O
the	O
VXLAN	B-Protocol
technology	O
include	O
Huawei	O
,	O
Broadcom	O
,	O
Citrix	B-Application
,	O
Pica8	O
,	O
Big	O
Switch	O
Networks	O
,	O
Cumulus	O
Networks	O
,	O
Dell	O
EMC	O
,	O
Ericsson	O
,	O
Mellanox	O
,	O
FreeBSD	B-Operating_System
,	O
OpenBSD	B-Operating_System
,	O
Red	O
Hat	O
,	O
Joyent	B-General_Concept
,	O
and	O
Juniper	O
Networks	O
.	O
</s>
<s>
VXLAN	B-Protocol
is	O
officially	O
documented	O
by	O
the	O
IETF	O
in	O
RFC	O
7348	O
.	O
</s>
<s>
VXLAN	B-Protocol
encapsulates	O
a	O
MAC	B-Protocol
frame	I-Protocol
in	O
a	O
UDP	B-Protocol
datagram	I-Protocol
for	O
transport	O
across	O
an	O
IP	O
network	O
,	O
creating	O
an	O
overlay	B-Architecture
network	I-Architecture
or	O
tunnel	B-Protocol
.	O
</s>
<s>
Open	B-Language
vSwitch	I-Language
is	O
an	O
example	O
of	O
a	O
software-based	O
virtual	B-Protocol
network	I-Protocol
switch	O
that	O
supports	O
VXLAN	B-Protocol
overlay	B-Architecture
networks	I-Architecture
.	O
</s>
