ZyXEL Communications P-791R, User Manual

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Chapter 7 Network Address Translation (NAT) Screens
P-791R v2 User’s Guide
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7.3 NAT General Setup
You must create a firewall rule in addition to setting up SUA/NAT, to allow traffic from the
WAN to be forwarded through the ZyXEL Device. Click
Network > NAT to open the
following screen.
Figure 42 NAT > General
The following table describes the labels in this screen.
7.4 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.
Table 25 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.
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 using
all of the available NAT sessions.
Enable SIP
ALG
Select this to make sure SIP (VoIP) works correctly with port-forwarding and port-
triggering rules.
Apply Click Apply to save your changes back to the ZyXEL Device.
Cancel Click Cancel to reload the previous configuration for this screen.