<s>
Amazon	B-General_Concept
Virtual	I-General_Concept
Private	I-General_Concept
Cloud	I-General_Concept
(	O
VPC	B-General_Concept
)	O
is	O
a	O
commercial	O
cloud	B-Architecture
computing	I-Architecture
service	O
that	O
provides	O
a	O
virtual	B-General_Concept
private	I-General_Concept
cloud	I-General_Concept
,	O
by	O
“	O
provisioning	O
a	O
logically	O
isolated	O
section	O
of	O
Amazon	B-Application
Web	I-Application
Services	I-Application
(	O
AWS	B-Application
)	O
Cloud	O
”	O
.	O
</s>
<s>
Enterprise	B-General_Concept
customers	O
are	O
able	O
to	O
access	O
the	O
Amazon	B-General_Concept
Elastic	I-General_Concept
Compute	I-General_Concept
Cloud	I-General_Concept
(	O
EC2	O
)	O
over	O
an	O
IPsec	B-Protocol
based	O
virtual	B-Application
private	I-Application
network	I-Application
.	O
</s>
<s>
Unlike	O
traditional	O
EC2	O
instances	O
which	O
are	O
allocated	O
internal	O
and	O
external	O
IP	O
numbers	O
by	O
Amazon	B-Application
,	O
the	O
customer	O
can	O
assign	O
IP	O
numbers	O
of	O
their	O
choosing	O
from	O
one	O
or	O
more	O
subnets	O
.	O
</s>
<s>
By	O
giving	O
the	O
user	O
the	O
option	O
of	O
selecting	O
which	O
AWS	B-Application
resources	O
are	O
public	O
facing	O
and	O
which	O
are	O
not	O
,	O
VPC	B-General_Concept
provides	O
much	O
more	O
granular	O
control	O
over	O
security	O
.	O
</s>
<s>
For	O
Amazon	B-Application
it	O
is	O
“	O
an	O
endorsement	O
of	O
the	O
hybrid	O
approach	O
,	O
but	O
it	O
's	O
also	O
meant	O
to	O
combat	O
the	O
growing	O
interest	O
in	O
private	O
clouds	O
”	O
.	O
</s>
<s>
Amazon	B-General_Concept
Virtual	I-General_Concept
Private	I-General_Concept
Cloud	I-General_Concept
aims	O
to	O
provide	O
a	O
service	O
similar	O
to	O
private	O
clouds	O
using	O
technology	O
such	O
as	O
OpenStack	B-Application
or	O
HPE	B-General_Concept
Helion	I-General_Concept
Eucalyptus	I-General_Concept
.	O
</s>
<s>
However	O
,	O
private	O
clouds	O
typically	O
use	O
technology	O
such	O
as	O
OpenShift	B-General_Concept
application	O
hosting	O
and	O
various	O
database	O
systems	O
.	O
</s>
<s>
If	O
transaction	O
records	O
are	O
requested	O
from	O
Amazon	B-Application
about	O
a	O
VPC	B-General_Concept
using	O
a	O
national	O
security	O
letter	O
they	O
may	O
not	O
be	O
legally	O
allowed	O
to	O
inform	O
the	O
customer	O
of	O
the	O
breach	O
of	O
the	O
security	O
of	O
their	O
system	O
.	O
</s>
<s>
This	O
would	O
be	O
true	O
even	O
if	O
the	O
actual	O
VPC	B-General_Concept
resources	O
were	O
in	O
another	O
country	O
.	O
</s>
<s>
The	O
API	O
used	O
by	O
AWS	B-Application
is	O
only	O
partly	O
compatible	O
with	O
that	O
of	O
HPE	B-General_Concept
Helion	I-General_Concept
Eucalyptus	I-General_Concept
and	O
is	O
not	O
compatible	O
with	O
other	O
private	O
cloud	O
systems	O
,	O
so	O
migration	O
from	O
AWS	B-Application
may	O
be	O
difficult	O
.	O
</s>
<s>
IP	O
Addressing	O
in	O
Amazon	B-General_Concept
Virtual	I-General_Concept
Private	I-General_Concept
Cloud	I-General_Concept
(	O
VPC	B-General_Concept
)	O
refers	O
to	O
the	O
assignment	O
of	O
IP	O
addresses	O
to	O
the	O
resources	O
within	O
a	O
VPC	B-General_Concept
.	O
</s>
<s>
VPC	B-General_Concept
is	O
Amazon	B-Application
Web	I-Application
Services	I-Application
 '	O
(	O
AWS	B-Application
)	O
solution	O
for	O
providing	O
isolated	O
network	O
environments	O
for	O
AWS	B-Application
resources	O
.	O
</s>
<s>
IP	O
addresses	O
in	O
a	O
VPC	B-General_Concept
are	O
used	O
for	O
communication	O
between	O
resources	O
within	O
the	O
VPC	B-General_Concept
,	O
as	O
well	O
as	O
for	O
communication	O
between	O
the	O
VPC	B-General_Concept
and	O
the	O
Internet	O
.	O
</s>
<s>
There	O
are	O
two	O
types	O
of	O
IP	O
addresses	O
used	O
in	O
a	O
VPC	B-General_Concept
:	O
private	B-Protocol
IP	I-Protocol
addresses	I-Protocol
and	O
public	O
IP	O
addresses	O
.	O
</s>
<s>
Private	B-Protocol
IP	I-Protocol
addresses	I-Protocol
are	O
used	O
for	O
communication	O
between	O
instances	O
within	O
the	O
VPC	B-General_Concept
,	O
while	O
public	O
IP	O
addresses	O
are	O
used	O
for	O
communication	O
between	O
the	O
VPC	B-General_Concept
and	O
the	O
Internet	O
.	O
</s>
<s>
Amazon	B-General_Concept
VPC	I-General_Concept
provides	O
several	O
options	O
for	O
IP	O
address	O
management	O
,	O
including	O
the	O
use	O
of	O
IPv4	O
and	O
IPv6	O
addresses	O
,	O
automatic	O
assignment	O
of	O
private	B-Protocol
IP	I-Protocol
addresses	I-Protocol
,	O
and	O
the	O
ability	O
to	O
assign	O
static	O
private	B-Protocol
IP	I-Protocol
addresses	I-Protocol
.	O
</s>
<s>
Additionally	O
,	O
Amazon	B-General_Concept
VPC	I-General_Concept
provides	O
the	O
option	O
to	O
associate	O
Elastic	B-General_Concept
IP	I-General_Concept
addresses	I-General_Concept
with	O
instances	O
to	O
ensure	O
persistent	O
public	O
IP	O
addresses	O
.	O
</s>
<s>
By	O
using	O
Amazon	B-General_Concept
VPC	I-General_Concept
,	O
customers	O
can	O
have	O
full	O
control	O
over	O
the	O
network	O
configuration	O
of	O
their	O
AWS	B-Application
resources	O
,	O
providing	O
increased	O
security	O
and	O
isolation	O
compared	O
to	O
the	O
traditional	O
shared-tenancy	O
model	O
of	O
public	O
cloud	B-Architecture
computing	I-Architecture
.	O
</s>
<s>
AWS	B-Application
VPC	B-General_Concept
allows	O
users	O
to	O
connect	O
to	O
the	O
Internet	O
,	O
a	O
user	O
's	O
corporate	O
data	B-Operating_System
center	I-Operating_System
,	O
and	O
other	O
users	O
 '	O
VPCs	O
.	O
</s>
<s>
Users	O
are	O
able	O
to	O
connect	O
to	O
the	O
Internet	O
by	O
adding	O
an	O
Internet	O
Gateway	O
to	O
their	O
VPC	B-General_Concept
,	O
which	O
assigns	O
the	O
VPC	B-General_Concept
a	O
public	O
IPv4	O
Address	O
.	O
</s>
<s>
Users	O
are	O
able	O
to	O
connect	O
to	O
a	O
data	B-Operating_System
center	I-Operating_System
by	O
setting	O
up	O
a	O
hardware	O
virtual	B-Application
private	I-Application
network	I-Application
connection	O
between	O
the	O
data	B-Operating_System
center	I-Operating_System
and	O
the	O
VPC	B-General_Concept
.	O
</s>
<s>
Users	O
are	O
also	O
able	O
to	O
route	O
traffic	O
from	O
one	O
VPC	B-General_Concept
to	O
another	O
VPC	B-General_Concept
using	O
private	B-Protocol
IP	I-Protocol
addresses	I-Protocol
,	O
and	O
are	O
able	O
to	O
communicate	O
as	O
if	O
they	O
were	O
on	O
the	O
same	O
network	O
.	O
</s>
<s>
VPC	B-General_Concept
peering	O
is	O
a	O
one-to-one	O
connection	O
,	O
but	O
users	O
are	O
able	O
to	O
connect	O
to	O
more	O
than	O
one	O
VPC	B-General_Concept
at	O
a	O
time	O
.	O
</s>
<s>
AWS	B-Application
VPC	B-General_Concept
's	O
security	O
is	O
two-fold	O
:	O
firstly	O
,	O
AWS	B-Application
VPC	B-General_Concept
uses	O
security	O
groups	O
as	O
a	O
firewall	O
to	O
control	O
traffic	O
at	O
the	O
instance	O
level	O
,	O
while	O
it	O
also	O
uses	O
network	O
access	O
control	O
lists	O
as	O
a	O
firewall	O
to	O
control	O
traffic	O
at	O
the	O
subnet	O
level	O
.	O
</s>
<s>
As	O
another	O
measure	O
of	O
privacy	O
,	O
AWS	B-Application
VPC	B-General_Concept
provides	O
users	O
with	O
ability	O
to	O
create	O
“	O
dedicated	O
instances	O
”	O
on	O
hardware	O
,	O
physically	O
isolating	O
the	O
dedicated	O
instances	O
from	O
non-dedicated	O
instances	O
and	O
instances	O
owned	O
by	O
other	O
accounts	O
.	O
</s>
<s>
AWS	B-Application
VPC	B-General_Concept
is	O
free	O
,	O
with	O
users	O
only	O
paying	O
for	O
the	O
consumption	O
of	O
EC2	O
resources	O
.	O
</s>
<s>
However	O
,	O
if	O
users	O
choose	O
to	O
access	O
VPC	B-General_Concept
via	O
a	O
Virtual	B-Application
Private	I-Application
Network	I-Application
(	O
VPN	B-Application
)	O
,	O
there	O
is	O
a	O
charge	O
.	O
</s>
