ZyXEL Communications NR2101, User Manual

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Chapter 8 NAT
NR2101 User’s Guide
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The following table summarizes how these NAT types handle outgoing and incoming packets.
8.2 NAT Settings
Use this screen to enable IP Pass-Through , VPN Pass-Through, PPTP VPN Pass-Through , L2TP Pass-Through ,
and Webserver WWAN Access protocols. Click NAT SETTINGS to open the following screen.
Note: To select a NAT type from the Select NAT Type drop-down list box or edit DMZ IP, you
must disable IP Pass-Through .
Figure 87 NAT SETTINGS
Table 32 NAT Types
FULL CONE
ADDRESS
RESTRICTED
PORT RESTRICTED SYMMETRIC
Incoming
Packets Any external host
can send packets to
the mapped
external IP address
and port. Only external hosts
with an IP address to
which the internal
host has already
sent a packet can
send packets to the
mapped external IP
address and port. Only external hosts
with an IP address
and port to which the
internal host has
already sent a packet
can send packets to
the mapped external
IP address and port. A host on the external
network can only send
packets to the specific
mapped external IP
address and port that the
NAT router used in sending
a packet to the external
host’s IP address and port.
Outgoing
Packets The NAT router maps the internal IP address and port of all outgoing
packets to a single IP address and port on the external network. The NAT router maps the
internal IP address and
port of each outgoing
packet to a different
external IP address and
port for each different
destination IP address and
port.