<s>
Static	B-Protocol
routing	I-Protocol
is	O
a	O
form	O
of	O
routing	B-Protocol
that	O
occurs	O
when	O
a	O
router	B-Protocol
uses	O
a	O
manually-configured	O
routing	B-Protocol
entry	O
,	O
rather	O
than	O
information	O
from	O
dynamic	B-Protocol
routing	I-Protocol
traffic	O
.	O
</s>
<s>
In	O
many	O
cases	O
,	O
static	B-Protocol
routes	I-Protocol
are	O
manually	O
configured	O
by	O
a	O
network	O
administrator	O
by	O
adding	O
in	O
entries	O
into	O
a	O
routing	B-Protocol
table	I-Protocol
,	O
though	O
this	O
may	O
not	O
always	O
be	O
the	O
case	O
.	O
</s>
<s>
Unlike	O
dynamic	B-Protocol
routing	I-Protocol
,	O
static	B-Protocol
routes	I-Protocol
are	O
fixed	O
and	O
do	O
not	O
change	O
if	O
the	O
network	O
is	O
changed	O
or	O
reconfigured	O
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
and	O
dynamic	B-Protocol
routing	I-Protocol
are	O
not	O
mutually	O
exclusive	O
.	O
</s>
<s>
Both	O
dynamic	B-Protocol
routing	I-Protocol
and	O
static	B-Protocol
routing	I-Protocol
are	O
usually	O
used	O
on	O
a	O
router	B-Protocol
to	O
maximise	O
routing	B-Protocol
efficiency	O
and	O
to	O
provide	O
backups	O
in	O
case	O
dynamic	B-Protocol
routing	I-Protocol
information	O
fails	O
to	O
be	O
exchanged	O
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
can	O
also	O
be	O
used	O
in	O
stub	B-Architecture
networks	I-Architecture
,	O
or	O
to	O
provide	O
a	O
gateway	B-Protocol
of	I-Protocol
last	I-Protocol
resort	I-Protocol
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
may	O
have	O
the	O
following	O
uses	O
:	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
can	O
be	O
used	O
to	O
define	O
an	O
exit	O
point	O
from	O
a	O
router	B-Protocol
when	O
no	O
other	O
routes	O
are	O
available	O
or	O
necessary	O
.	O
</s>
<s>
This	O
is	O
called	O
a	O
default	B-Protocol
route	I-Protocol
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
can	O
be	O
used	O
for	O
small	O
networks	O
that	O
require	O
only	O
one	O
or	O
two	O
routes	O
.	O
</s>
<s>
This	O
is	O
often	O
more	O
efficient	O
since	O
a	O
link	O
is	O
not	O
being	O
wasted	O
by	O
exchanging	O
dynamic	B-Protocol
routing	I-Protocol
information	O
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
is	O
often	O
used	O
as	O
a	O
complement	O
to	O
dynamic	B-Protocol
routing	I-Protocol
to	O
provide	O
a	O
failsafe	O
backup	O
if	O
a	O
dynamic	B-Protocol
route	I-Protocol
is	O
unavailable	O
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
is	O
often	O
used	O
to	O
help	O
transfer	O
routing	B-Protocol
information	I-Protocol
from	O
one	O
routing	B-Protocol
protocol	I-Protocol
to	O
another	O
(	O
routing	B-Protocol
redistribution	O
)	O
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
,	O
if	O
used	O
without	O
dynamic	B-Protocol
routing	I-Protocol
,	O
has	O
the	O
following	O
advantages	O
:	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
causes	O
very	O
little	O
load	O
on	O
the	O
CPU	B-Device
of	O
the	O
router	B-Protocol
,	O
and	O
produces	O
no	O
traffic	O
to	O
other	O
routers	B-Protocol
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
leaves	O
the	O
network	O
administrator	O
with	O
full	O
control	O
over	O
the	O
routing	B-Protocol
behavior	O
of	O
the	O
network	O
.	O
</s>
<s>
Static	B-Protocol
Routing	I-Protocol
is	O
very	O
easy	O
to	O
configure	O
on	O
small	O
networks	O
.	O
</s>
<s>
Static	B-Protocol
routing	I-Protocol
can	O
have	O
some	O
potential	O
disadvantages	O
:	O
</s>
<s>
Human	O
error	O
:	O
In	O
many	O
cases	O
,	O
static	B-Protocol
routes	I-Protocol
are	O
manually	O
configured	O
.	O
</s>
<s>
Administrators	O
can	O
make	O
mistakes	O
and	O
mistype	O
in	O
network	O
information	O
,	O
or	O
configure	O
incorrect	O
routing	B-Protocol
paths	O
by	O
mistake	O
.	O
</s>
<s>
Fault	O
tolerance	O
:	O
Static	B-Protocol
routing	I-Protocol
is	O
not	O
fault	O
tolerant	O
.	O
</s>
<s>
This	O
means	O
that	O
when	O
there	O
is	O
a	O
change	O
in	O
the	O
network	O
or	O
a	O
failure	O
occurs	O
between	O
two	O
statically	O
defined	O
devices	O
,	O
traffic	O
will	O
not	O
be	O
re-routed	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
the	O
network	O
is	O
unusable	O
until	O
the	O
failure	O
is	O
repaired	O
or	O
the	O
static	B-Protocol
route	I-Protocol
is	O
manually	O
reconfigured	O
by	O
an	O
administrator	O
.	O
</s>
<s>
Administrative	B-Protocol
distance	I-Protocol
:	O
Static	B-Protocol
routes	I-Protocol
typically	O
take	O
precedence	O
over	O
routes	O
configured	O
with	O
a	O
dynamic	B-Protocol
routing	I-Protocol
protocol	O
.	O
</s>
<s>
This	O
means	O
that	O
static	B-Protocol
routes	I-Protocol
may	O
prevent	O
routing	B-Protocol
protocols	I-Protocol
from	O
working	O
as	O
intended	O
.	O
</s>
<s>
A	O
solution	O
is	O
to	O
manually	O
modify	O
the	O
administrative	B-Protocol
distance	I-Protocol
.	O
</s>
<s>
Administrative	O
overhead	O
:	O
Static	B-Protocol
routes	I-Protocol
must	O
be	O
configured	O
on	O
each	O
router	B-Protocol
in	O
the	O
network(s )	O
.	O
</s>
<s>
This	O
configuration	O
can	O
take	O
a	O
long	O
time	O
if	O
there	O
are	O
many	O
routers	B-Protocol
.	O
</s>
<s>
Dynamic	B-Protocol
routing	I-Protocol
on	O
the	O
other	O
hand	O
automatically	O
propagates	O
routing	B-Protocol
changes	O
,	O
reducing	O
the	O
need	O
for	O
manual	O
reconfiguration	O
.	O
</s>
<s>
To	O
route	O
IP	B-Protocol
traffic	O
destined	O
for	O
the	O
network	O
10.10.20.0/24	O
via	O
the	O
next-hop	O
router	B-Protocol
with	O
the	O
IPv4	O
address	O
of	O
192.168.100.1	O
,	O
the	O
following	O
configuration	O
commands	O
or	O
steps	O
can	O
be	O
used	O
:	O
</s>
<s>
In	O
most	O
Linux	O
distributions	O
,	O
a	O
static	B-Protocol
route	I-Protocol
can	O
be	O
added	O
using	O
the	O
iproute2	B-Protocol
command	O
.	O
</s>
<s>
Enterprise-level	O
Cisco	O
routers	B-Protocol
are	O
configurable	O
using	O
the	O
Cisco	O
IOS	O
command	O
line	O
,	O
rather	O
than	O
a	O
web	O
management	O
interface	O
.	O
</s>
<s>
The	O
commands	O
to	O
add	O
a	O
static	B-Protocol
route	I-Protocol
are	O
as	O
follows	O
:	O
</s>
<s>
Network	O
configurations	O
are	O
not	O
restricted	O
to	O
a	O
single	O
static	B-Protocol
route	I-Protocol
per	O
destination	O
:	O
</s>
<s>
The	O
administrative	B-Protocol
distance	I-Protocol
can	O
be	O
manually	O
(	O
re	O
)	O
configured	O
so	O
that	O
the	O
static	B-Protocol
route	I-Protocol
can	O
be	O
configured	O
as	O
a	O
backup	O
route	O
,	O
to	O
be	O
used	O
only	O
if	O
the	O
dynamic	B-Protocol
route	I-Protocol
is	O
unavailable	O
.	O
</s>
<s>
Setting	O
the	O
administrative	B-Protocol
distance	I-Protocol
to	O
254	O
will	O
result	O
in	O
the	O
route	O
being	O
used	O
only	O
as	O
a	O
backup	O
.	O
</s>
