<s>
Amazon	B-Protocol
Route	I-Protocol
53	I-Protocol
(	O
Route	O
53	O
)	O
is	O
a	O
scalable	O
and	O
highly	O
available	O
Domain	B-Protocol
Name	I-Protocol
System	I-Protocol
(	O
DNS	B-Protocol
)	O
service	O
.	O
</s>
<s>
Released	O
on	O
December	O
5	O
,	O
2010	O
,	O
it	O
is	O
part	O
of	O
com	O
's	O
cloud	B-Architecture
computing	I-Architecture
platform	I-Architecture
,	O
Amazon	B-Application
Web	I-Application
Services	I-Application
(	O
AWS	B-Application
)	O
.	O
</s>
<s>
Routes	O
,	O
and	O
"	O
53	O
"	O
is	O
a	O
reference	O
to	O
the	O
TCP/UDP	O
port	O
53	O
,	O
where	O
DNS	B-Protocol
server	I-Protocol
requests	O
are	O
addressed	O
.	O
</s>
<s>
In	O
addition	O
to	O
being	O
able	O
to	O
route	O
users	O
to	O
various	O
AWS	B-Application
services	O
,	O
including	O
EC2	B-General_Concept
instances	O
,	O
Route	O
53	O
also	O
enables	O
AWS	B-Application
customers	O
to	O
route	O
users	O
to	O
non-AWS	O
infrastructure	O
and	O
to	O
monitor	O
the	O
health	O
of	O
their	O
application	O
and	O
its	O
endpoints	O
.	O
</s>
<s>
Amazon	B-Protocol
Route	I-Protocol
53	I-Protocol
supports	O
full	O
,	O
end-to-end	O
DNS	B-Protocol
resolution	O
over	O
IPv6	O
.	O
</s>
<s>
Recursive	O
DNS	B-Protocol
resolvers	O
on	O
IPv6	O
networks	O
can	O
use	O
either	O
IPv4	O
or	O
IPv6	O
transport	O
to	O
send	O
DNS	B-Protocol
queries	I-Protocol
to	O
Amazon	B-Protocol
Route	I-Protocol
53	I-Protocol
.	O
</s>
<s>
Customers	O
create	O
"	O
hosted	O
zones	O
"	O
that	O
act	O
as	O
a	O
container	O
for	O
four	O
name	B-Protocol
servers	I-Protocol
.	O
</s>
<s>
The	O
name	B-Protocol
servers	I-Protocol
are	O
spread	O
across	O
four	O
different	O
TLDs	O
.	O
</s>
<s>
Customers	O
are	O
able	O
to	O
add	O
,	O
delete	O
,	O
and	O
change	O
any	O
DNS	B-Protocol
records	O
in	O
their	O
hosted	O
zones	O
.	O
</s>
<s>
Amazon	B-Application
also	O
offers	O
domain	O
registration	O
services	O
to	O
AWS	B-Application
customers	O
through	O
Route	O
53	O
.	O
</s>
<s>
Amazon	B-Application
provides	O
an	O
SLA	O
of	O
the	O
service	O
always	O
being	O
available	O
at	O
all	O
times	O
(	O
100%	O
available	O
)	O
.	O
</s>
<s>
One	O
of	O
the	O
key	O
features	O
of	O
Route	O
53	O
is	O
programmatic	O
access	O
to	O
the	O
service	O
that	O
allows	O
customers	O
to	O
modify	O
DNS	B-Protocol
records	O
via	O
web	O
service	O
calls	O
.	O
</s>
<s>
Combined	O
with	O
other	O
features	O
in	O
AWS	B-Application
,	O
this	O
allows	O
a	O
developer	O
to	O
programmatically	O
bring	O
up	O
a	O
machine	O
and	O
point	O
to	O
components	O
that	O
have	O
been	O
created	O
via	O
other	O
service	O
calls	O
such	O
as	O
those	O
to	O
create	O
new	O
S3	B-General_Concept
buckets	O
or	O
EC2	B-General_Concept
instances	O
.	O
</s>
<s>
Alias	O
records	O
act	O
similarly	O
to	O
CNAME	B-Protocol
records	I-Protocol
but	O
are	O
resolved	O
on	O
the	O
server	O
side	O
and	O
appear	O
to	O
clients	O
as	O
an	O
A	O
record	O
.	O
</s>
<s>
They	O
can	O
be	O
used	O
to	O
create	O
transparent	O
references	O
to	O
other	O
AWS	B-Application
resources	O
that	O
only	O
provide	O
DNS	B-Protocol
names	I-Protocol
and	O
not	O
IP	O
addresses	O
,	O
such	O
as	O
an	O
Elastic	B-General_Concept
Load	I-General_Concept
Balancer	I-General_Concept
or	O
a	O
CloudFront	O
distribution	O
.	O
</s>
<s>
Because	O
alias	O
records	O
are	O
resolved	O
on	O
the	O
server-side	O
and	O
return	O
A	O
records	O
to	O
clients	O
they	O
can	O
be	O
used	O
in	O
domain	O
apex	O
records	O
in	O
a	O
similar	O
way	O
to	O
a	O
CNAME	B-Protocol
record	I-Protocol
,	O
where	O
CNAME	B-Protocol
records	I-Protocol
are	O
disallowed	O
for	O
this	O
use	O
by	O
RFC	O
2181	O
.	O
</s>
