3
Addressing
61
Creating ARP entries
To
change
the
way
the
SEG
handles
ARP
on
an
interface,
you
can
create
SEG
ARP
objects,
each
of
which
has
the
following
properties:
•
Mode:
The
type
of
ARP
object.
This
can
be
one
of:
•
Static
–
Create
a
fixed
mapping
in
the
local
ARP
cache.
•
Publish
–
Publish
an
IP
address
on
a
particular
MAC
address
(or
this
interface).
•
Interface:
The
local
physical
interface
for
the
ARP
object.
•
IP
Address:
The
IPv4
address
for
the
MAC/IP
mapping.
•
MAC
Address:
The
MAC
address
for
the
MAC/IP
mapping.
Static ARP objects
A
static
ARP
object
can
be
used
to
insert
a
particular
MAC/IP
address
mapping
into
the
SEG
ARP
cache.
The
most
frequent
use
of
static
ARP
objects
is
in
situations
where
some
external
network
device
is
not
responding
to
ARP
requests
correctly
and
is
reporting
an
incorrect
MAC
address.
Some
network
devices,
such
as
wireless
modems,
may
have
such
problems.
A
frequent
source
of
confusion
is
that
this
mode
is
not
for
publishing
the
address
for
external
devices.
Instead,
static
entries
allow
the
administrator
to
tell
the
SEG
how
to
reach
external
devices.
The
entry
tells
the
SEG
that
a
specific
IPv4
address
can
be
reached
through
a
specific
interface
using
a
specific
MAC
address.
This
means
that
when
the
SEG
needs
to
communicate
with
the
address,
it
consults
the
ARP
table
static
entries
and
can
determine
it
can
be
reached
at
a
specific
MAC
address
on
a
specific
interface.
This
feature
may
also
be
used
to
lock
an
IP
address
to
a
specific
MAC
address
for
increasing
security
or
to
avoid
denial
‐
of
‐
service
if
there
are
unauthorized
users
in
a
network.
However,
such
protection
applies
only
to
packets
being
sent
to
that
IP
address.
It
does
not
apply
to
packets
being
sent
from
the
IP
address
since
the
source
MAC
address
can
be
forged.
Example: Creating a static ARP entry
This
example
will
create
a
static
mapping
between
IPv4
address
192.168.10.15
and
MAC
address
4b:86:f6:c5:a2:14
on
the
sfp2
interface:
1. Change
the
context
to
be
ARPEntries
:
Device:/>
cc
ARPEntries
2. Add
an
ARPEntry
object
to
ARPEntries
:
Device:/ARPEntries>
add
ARPEntry
Interface=sfp2
IP=192.168.10.15
Mode=Static
MACAddress=4b
‐
86
‐
f6
‐
c5
‐
a2
‐
14
3. Finally,
return
to
the
default
root
context:
Device:/ARPEntries>
cc
Device:/>
