PoE
AP
Router
118
RIP
Scenario
The
Routing
Information
Protocol
(RIP)
is
one
of
the
oldest
distance
‐
vector
routing
protocols,
which
employs
the
hop
count
as
a
routing
metric.
RIP
prevents
routing
loops
by
implementing
a
limit
on
the
number
of
hops
allowed
in
a
path
from
the
source
to
a
destination.
The
maximum
number
of
hops
allowed
for
RIP
is
15.
This
hop
limit,
however,
also
limits
the
size
of
networks
that
RIP
can
support.
A
hop
count
of
16
is
considered
an
infinite
distance,
in
other
words
the
route
is
considered
unreachable.
RIP
implements
the
split
horizon,
route
poisoning
and
hold
‐
down
mechanisms
to
prevent
incorrect
routing
information
from
being
propagated.
OSPF
Scenario
Open
Shortest
Path
First
(OSPF)
is
a
routing
protocol
that
uses
link
state
routing
algorithm.
It
is
the
most
widely
used
interior
gateway
protocol
(IGP)
in
large
enterprise
networks.
It
gathers
link
state
information
from
available
routers
and
constructs
a
topology
map
of
the
network.
The
topology
is
presented
as
a
routing
table
which
routes
datagrams
based
solely
on
the
destination
IP
address.
Network
administrator
can
deploy
OSPF
gateway
in
large
enterprise
network
to
get
its
routing
table
from
the
enterprise
backbone,
and
forward
routing
information
to
other
routers,
which
are
no
linked
to
the
enterprise
backbone.
Usually,
an
OSPF
network
is
subdivided
into
routing
areas
to
simplify
administration
and
optimize
traffic
and
resource
utilization.
As
shown
in
the
diagram,
OSPF
gateway
gathers
routing
information
from
the
backbone
gateways
in
area
0,
and
will
forward
its
routing
information
to
the
routers
in
area
1
and
area
2
which
are
not
in
the
backbone.
