<s>
A	O
virtual	B-Protocol
security	I-Protocol
switch	I-Protocol
is	O
a	O
software	O
Ethernet	B-Protocol
switch	I-Protocol
with	O
embedded	O
security	O
controls	O
within	O
it	O
that	O
runs	O
within	O
virtual	B-General_Concept
environments	I-General_Concept
such	O
as	O
VMware	B-Application
vSphere	I-Application
,	O
Citrix	B-General_Concept
XenDesktop	I-General_Concept
,	O
Microsoft	O
Hyper-V	O
and	O
Virtual	O
Iron	O
.	O
</s>
<s>
The	O
primary	O
purpose	O
of	O
a	O
virtual	B-Protocol
security	I-Protocol
switch	I-Protocol
is	O
to	O
provide	O
security	O
measures	O
such	O
as	O
isolation	O
,	O
control	O
and	O
content	O
inspection	O
between	O
virtual	B-Architecture
machines	I-Architecture
.	O
</s>
<s>
Virtual	B-Architecture
machines	I-Architecture
within	O
enterprise	B-Application
server	I-Application
environments	O
began	O
to	O
gain	O
popularity	O
in	O
2005	O
and	O
quickly	O
started	O
to	O
become	O
a	O
standard	O
in	O
the	O
way	O
companies	O
deploy	O
servers	O
and	O
applications	O
.	O
</s>
<s>
In	O
order	O
to	O
deploy	O
these	O
servers	O
within	O
a	O
virtual	O
environment	O
,	O
a	O
virtual	B-Protocol
network	I-Protocol
needed	O
to	O
be	O
formed	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
companies	O
such	O
as	O
VMware	O
created	O
a	O
resource	O
called	O
a	O
virtual	B-Architecture
switch	I-Architecture
.	O
</s>
<s>
The	O
purpose	O
of	O
the	O
virtual	B-Architecture
switch	I-Architecture
was	O
to	O
provide	O
network	O
connectivity	O
within	O
the	O
virtual	O
environment	O
so	O
that	O
virtual	B-Architecture
machines	I-Architecture
and	O
applications	O
could	O
communicate	O
within	O
the	O
virtual	B-Protocol
network	I-Protocol
as	O
well	O
as	O
with	O
the	O
physical	O
network	O
.	O
</s>
<s>
This	O
concept	O
of	O
a	O
virtual	B-Protocol
network	I-Protocol
introduced	O
a	O
number	O
of	O
problems	O
,	O
as	O
it	O
related	O
to	O
security	O
within	O
virtual	O
environment	O
,	O
due	O
to	O
only	O
having	O
virtual	O
switching	O
technology	O
within	O
the	O
environment	O
and	O
not	O
security	O
technologies	O
.	O
</s>
<s>
Unlike	O
physical	O
networks	O
that	O
have	O
switches	O
with	O
access	O
control	O
lists	O
(	O
ACLs	O
)	O
,	O
firewalls	B-Application
,	O
antivirus	B-Application
gateways	O
,	O
or	O
intrusion	O
prevention	O
devices	O
,	O
the	O
virtual	B-Protocol
network	I-Protocol
was	O
wide	O
open	O
.	O
</s>
<s>
The	O
virtual	B-Protocol
security	I-Protocol
switch	I-Protocol
concept	O
is	O
one	O
where	O
switching	O
and	O
security	O
have	O
joined	O
forces	O
,	O
so	O
that	O
security	O
controls	O
could	O
be	O
placed	O
within	O
the	O
virtual	B-Architecture
switch	I-Architecture
and	O
provide	O
per-port	O
inspection	O
and	O
isolation	O
within	O
the	O
virtual	O
environment	O
.	O
</s>
<s>
This	O
concept	O
allowed	O
security	O
to	O
get	O
as	O
close	O
as	O
possible	O
to	O
the	O
end	O
points	O
that	O
it	O
intends	O
to	O
protect	O
,	O
without	O
having	O
to	O
reside	O
on	O
the	O
end	O
points	O
(	O
host-based	O
on	O
virtual	B-Architecture
machines	I-Architecture
)	O
themselves	O
.	O
</s>
<s>
By	O
eliminating	O
the	O
need	O
to	O
deploy	O
host-based	O
security	O
solutions	O
on	O
virtual	B-Architecture
machines	I-Architecture
,	O
a	O
significant	O
performance	O
improvement	O
can	O
be	O
achieved	O
when	O
deploying	O
security	O
within	O
the	O
virtual	O
environment	O
.	O
</s>
<s>
This	O
is	O
because	O
virtual	B-Architecture
machines	I-Architecture
share	O
computing	O
resources	O
(	O
e.g.	O
</s>
<s>
CPU	B-Device
time	O
,	O
memory	B-Architecture
or	O
disk	B-General_Concept
space	I-General_Concept
)	O
while	O
physical	O
servers	O
that	O
have	O
dedicated	O
resources	O
.	O
</s>
<s>
One	O
way	O
of	O
understanding	O
this	O
,	O
is	O
to	O
picture	O
20	O
virtual	B-Architecture
machines	I-Architecture
running	O
on	O
a	O
dual-CPU	O
server	B-Application
and	O
each	O
virtual	O
server	B-Application
having	O
its	O
own	O
host-based	B-Application
firewall	I-Application
running	O
on	O
them	O
.	O
</s>
<s>
This	O
would	O
make	O
up	O
20	O
firewalls	B-Application
using	O
the	O
same	O
resources	O
that	O
the	O
20	O
virtual	B-Architecture
machines	I-Architecture
are	O
using	O
.	O
</s>
<s>
This	O
defeats	O
the	O
purpose	O
of	O
virtualization	B-General_Concept
,	O
which	O
is	O
to	O
apply	O
those	O
resources	O
to	O
virtual	O
servers	O
not	O
security	O
applications	O
.	O
</s>
<s>
Deploying	O
security	O
centrally	O
within	O
the	O
virtual	O
environment	O
is	O
in	O
a	O
sense	O
one	O
firewall	B-Application
versus	O
20	O
firewalls	B-Application
.	O
</s>
<s>
Because	O
switches	O
are	O
layer	B-Protocol
2	I-Protocol
devices	O
that	O
create	O
a	O
single	O
broadcast	O
domain	O
,	O
virtual	B-Protocol
security	I-Protocol
switches	I-Protocol
alone	O
cannot	O
fully	O
replicate	O
the	O
network	O
segmentation	O
and	O
isolation	O
typically	O
employed	O
in	O
a	O
multi-tiered	O
physical	O
network	O
.	O
</s>
<s>
To	O
address	O
this	O
limitation	O
,	O
a	O
number	O
of	O
networking	O
,	O
security	O
and	O
virtualization	B-General_Concept
vendors	O
have	O
begun	O
to	O
offer	O
virtual	B-Protocol
firewalls	I-Protocol
,	O
virtual	O
routers	B-Protocol
and	O
other	O
network	O
devices	O
to	O
allow	O
virtual	B-Protocol
networks	I-Protocol
to	O
offer	O
more	O
robust	O
security	O
and	O
network	O
organization	O
solutions	O
.	O
</s>
<s>
Because	O
virtual	B-Architecture
machines	I-Architecture
are	O
essentially	O
operating	B-General_Concept
systems	I-General_Concept
and	O
applications	O
packaged	O
into	O
a	O
single	O
file	O
(	O
called	O
disk	B-Application
images	I-Application
)	O
,	O
they	O
have	O
now	O
become	O
more	O
mobile	O
.	O
</s>
<s>
For	O
the	O
first	O
time	O
in	O
history	O
,	O
servers	O
can	O
be	O
moved	O
around	O
,	O
exchanged	O
and	O
shared	O
just	O
like	O
MP3	B-Application
files	I-Application
shared	O
on	O
the	O
peer-to-peer	O
networks	O
.	O
</s>
<s>
Administrators	B-Application
can	O
now	O
download	O
pre-installed	O
virtual	O
servers	O
via	O
the	O
Internet	O
to	O
speed	O
up	O
the	O
deployment	O
time	O
of	O
new	O
servers	O
.	O
</s>
<s>
No	O
longer	O
is	O
it	O
required	O
for	O
an	O
administrator	O
to	O
go	O
through	O
the	O
lengthy	O
software	O
installation	O
process	O
,	O
because	O
these	O
virtual	O
disk	B-Application
images	I-Application
have	O
pre-installed	O
operating	B-General_Concept
systems	I-General_Concept
and	O
applications	O
.	O
</s>
<s>
They	O
are	O
virtual	B-Application
appliances	I-Application
.	O
</s>
<s>
This	O
mobility	O
of	O
server	B-Application
images	O
has	O
now	O
created	O
the	O
potential	O
problem	O
that	O
entire	O
servers	O
can	O
become	O
infected	O
and	O
passed	O
around	O
in	O
the	O
wild	O
.	O
</s>
<s>
Imagine	O
downloading	O
the	O
latest	O
Fedora	O
Linux	B-Application
Server	B-Application
from	O
a	O
web	O
site	O
like	O
ThoughtPolice.co.uk,	O
installing	O
it	O
and	O
later	O
learning	O
that	O
there	O
was	O
a	O
Trojan	O
horse	O
on	O
that	O
server	B-Application
that	O
later	O
took	O
down	O
your	O
virtual	B-Protocol
network	I-Protocol
.	O
</s>
<s>
While	O
there	O
is	O
the	O
trust	O
factor	O
that	O
now	O
needs	O
to	O
be	O
taken	O
in	O
account	O
when	O
downloading	O
virtual	O
server	B-Application
images	O
,	O
</s>
<s>
The	O
Virtual	B-Protocol
Security	I-Protocol
Switch	I-Protocol
concept	O
is	O
one	O
that	O
monitors	O
your	O
trust	O
decision	O
by	O
providing	O
isolation	O
and	O
security	O
monitoring	O
between	O
virtual	B-Architecture
machines	I-Architecture
.	O
</s>
<s>
A	O
Virtual	B-Protocol
Security	I-Protocol
Switch	I-Protocol
can	O
isolate	O
VM	O
’s	O
from	O
each	O
other	O
,	O
restrict	O
what	O
types	O
of	O
communication	O
is	O
allowed	O
between	O
each	O
other	O
as	O
well	O
as	O
monitor	O
for	O
the	O
spread	O
of	O
malicious	O
content	O
or	O
denial	O
of	O
service	O
attacks	O
.	O
</s>
<s>
In	O
2008	O
,	O
Vyatta	B-Protocol
began	O
to	O
ship	O
an	O
open	B-License
source	I-License
network	B-Protocol
operating	I-Protocol
system	I-Protocol
designed	O
to	O
offer	O
layer	B-Application
3	I-Application
services	O
such	O
as	O
routing	O
,	O
firewall	B-Application
,	O
network	B-Protocol
address	I-Protocol
translation	I-Protocol
(	O
NAT	O
)	O
,	O
dynamic	B-Protocol
host	I-Protocol
configuration	I-Protocol
and	O
virtual	B-Application
private	I-Application
network	I-Application
(	O
VPN	B-Application
)	O
within	O
and	O
between	O
hypervisors	B-Operating_System
.	O
</s>
<s>
Since	O
then	O
,	O
VMware	O
,	O
Cisco	O
,	O
Juniper	O
and	O
others	O
have	O
shipped	O
virtual	O
networking	O
security	O
products	O
that	O
incorporate	O
layer	B-Protocol
2	I-Protocol
and	O
layer	B-Application
3	I-Application
switching	O
and	O
routing	O
.	O
</s>
