Nat Application - ZyXEL Communications Nebula LTE3301-PLUS User Manual

11.6.4 NAT Application

The following figure illustrates a possible NAT application, where three inside LANs (logical LANs using IP
alias) behind the Zyxel Device can communicate with three distinct WAN networks.
Figure 132 NAT Application With IP Alias
Port Forwarding: Services and Port Numbers
The most often used port numbers are shown in the following table. Please refer to RFC 1700 for further
information about port numbers. Please also refer to the Supporting CD for more examples and details
on port forwarding and NAT.
Table 78 Services and Port Numbers
SERVICES
ECHO
FTP (File Transfer Protocol)
SMTP (Simple Mail Transfer Protocol)
DNS (Domain Name System)
Finger
HTTP (Hyper Text Transfer protocol or WWW, Web)
POP3 (Post Office Protocol)
Chapter 11 Network Address Translation (NAT)
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Nebula Mobile Router User's Guide
205
PORT NUMBER
7
21
25
53
79
80
110