M2M
Cellular
Gateway
Index
skipping
is
used
to
reserve
slots
for
new
function
insertion,
when
required.
269
beneath
the
"Configuration"
window.
Then
configure
parameters
on
another
gateway
to
take
another
role.
Above
diagram
is
the
server
role
configuration
and
following
diagram
shows
the
client
role
configuration.
When
you
want
to
configure
"L2TP
Server"
role
for
the
security
gateway,
there
are
4
more
configuration
windows:
"L2TP
Server
Configuration",
"L2TP
Server
Status",
"User
Account
List"
and
"User
Account
Configuration".
However,
when
you
want
to
configure
"L2TP
Client"
role
for
the
security
gateway,
there
are
3
more
configuration
windows:
"L2TP
Client
Configuration",
"L2TP
Client
List
&
Status"
and
"Configuration
for
A
L2TP
Client".
Configuration
The
"Configuration"
window
is
to
enable
the
L2TP
VPN
function
by
checking
the
Enable
box.
In
the
"Client/Server"
field
of
the
"Configuration"
window
choose
either
"Server"
or
"Client".
Choose
Server
to
define
the
gateway
as
the
L2TP
VPN
server
for
remote
clients
to
initiate
the
connection
to
establish
VPN
tunnels.
Or
choose
Client
to
create
multiple
L2TP
VPN
clients
to
establish
VPN
tunnels
to
remote
gateways.
Moreover,
the
security
gateway
serves
as
the
L2TP
VPN
client
and
server
simultaneously.
L2TP
VPN
Server
Scenario
When
you
want
the
security
gateway
to
play
a
L2TP
server
role,
check
the
"Enable"
box
and
choose
"Server"
option
in
the
"L2TP
Configuration"
window.
And
make
its
related
configuration
in
following
sessions.
Also
refer
to
the
above
server
role
diagram.
L2TP
Server
Configuration
In
the
"L2TP
Server
Configuration"
window
you
will
enable
L2TP
server
function
and
decide
if
you
want
L2TP
Server
to
support
L2TP
over
IPSec
connection
and
assign
the
IPSec
authentication
pre
‐
shared
key;
then
specify
the
virtual
IP
address
of
L2TP
server,
define
the
pool
of
virtual
IP
addresses
that
will
assign
to
remote
L2TP
clients
dialing
in
the
security
gateway,
and
the
authentication
protocol.
Once
you
select
"MS
‐
CHAP"
or
"MS
‐
CHAP
v2"
for
the
authentication
protocol,
you
also
can
specify
if
