Modbus
Cellular
Gateway
Index
skipping
is
used
to
reserve
slots
for
new
function
insertion,
when
required.
151
5.1.3
Packet
Filters
"Packet
Filters"
function
can
let
you
define
some
filtering
rules
for
incoming
and
outgoing
packets.
So
the
gateway
can
control
what
packets
are
allowed
or
blocked
to
pass
through
it.
A
packet
filter
rule
should
indicate
from
and
to
which
interface
the
packet
enters
and
leaves
the
gateway,
the
source
and
destination
IP
addresses,
and
destination
service
port
type
and
port
number.
Lastly,
the
time
schedule
to
which
the
rule
will
be
active.
In
"Packet
Filters"
page,
there
are
three
configuration
windows
for
packet
filtering
function.
They
are
the
"Configuration"
window,
"Packet
Filter
Rule
List"
window,
and
"Packet
Filter
Rule
Configuration"
window.
The
"Configuration"
window
can
let
you
activate
the
packet
filtering
function
and
specify
to
black
listing
or
to
white
listing
Inbound
or
Outbound
packets
defined
in
the
"Packet
Filter
Rule
List"
entry.
In
addition,
log
alerting
can
be
enabled
through
an
“Enable”
checkbox
to
log
events.
Second,
the
"Packet
Filter
Rule
List"
window
lists
all
your
defined
packet
filtering
rule
entry.
At
last,
the
"Packet
Filter
Rule
Configuration"
window
can
let
you
define
one
packet
filtering
rule.
Configuration
Check
the
"Enable"
box
to
activate
the
"Packet
Filters"
function.
Select
either
the
black
list
or
the
white
list
for
following
"Packet
Filter
Rule
List".
Finally,
enable
the
log
alerting
when
needed.
When
you
choose
"Allow
all
to
pass
except
those
match
the
following
rules"
for
the
"Packet
Filter
Rule
List",
you
are
setting
the
defined
packet
filtering
rules
to
belong
to
the
black
list.
The
packets,
listed
in
the
rule
list,
will
be
blocked
from
entering
or
leaving
the
gateway
if
they
match
to
one
rule.
Other
packets
can
pass
through
the
gateway.
In
contrast,
when
you
choose
"Deny
all
to
pass
except
those
match
the
following
rules"
for
the
"Packet
Filter
Rule
List",
you
are
setting
the
defined
packet
filtering
rules
to
belong
to
the
white
list.
The
packets,
listed
in
the
rule,
will
be
allowed
to
enter
or
leave
the
gateway
if
they
match
to
one
of
the
rules.
Other
packets
will
be
blocked.
