ZyXEL Communications P-2602HWLNI, Руководство пользователя, Страница: 159 / 496

Chapter 10 Network Address Translation (NAT) Screens
P-2602HWLNI User’s Guide
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Figure 91 NAT General
The following table describes the labels in this screen.
10.4 Port Forwarding
A port forwarding set is a list of inside (behind NAT on the LAN) servers, for example, web or
FTP, that you can make visible to the outside world even though NAT makes your whole
inside network appear as a single computer to the outside world.
You may enter a single port number or a range of port numbers to be forwarded, and the local
IP address of the desired server. The port number identifies a service; for example, web service
is on port 80 and FTP on port 21. In some cases, such as for unknown services or where one
server can support more than one service (for example both FTP and web service), it might be
better to specify a range of port numbers. You can allocate a server IP address that corresponds
to a port or a range of ports.
Table 53 NAT General
LABEL DESCRIPTION
Active
Network
Address
Translation
(NAT)
Select this check box to enable NAT.
SUA Only Select this radio button if you have just one public WAN IP address for your ZyXEL
Device.
Full Feature Select this radio button if you have multiple public WAN IP addresses for your ZyXEL
Device.
Max NAT/
Firewall
Session Per
User
When computers use peer to peer applications, such as file sharing applications, they
need to establish NAT sessions. If you do not limit the number of NAT sessions a
single client can establish, this can result in all of the available NAT sessions being
used. In this case, no additional NAT sessions can be established, and users may not
be able to access the Internet.
Each NAT session establishes a corresponding firewall session. Use this field to limit
the number of NAT/Firewall sessions client computers can establish through the
ZyXEL Device.
If your network has a small number of clients using peer to peer applications, you can
raise this number to ensure that their performance is not degraded by the number of
NAT sessions they can establish. If your network has a large number of users using
peer to peer applications, you can lower this number to ensure no single client is
exhausting all of the available NAT sessions.
Apply Click Apply to save your changes back to the ZyXEL Device.
Cancel Click Cancel to reload the previous configuration for this screen.