ZyXEL Communications Internet Security Gateway ZyWALL 2 Series - Manual (Page 128)

ZyWALL 2 Series User’s Guide
8-6 NAT
Table 8-3 Services and Port Numbers
SERVICES PORT NUMBER
DNS (Domain Name System) 53
Finger 79
HTTP (Hyper Text Transfer protocol or WWW, Web) 80
POP3 (Post Office Protocol) 110
NNTP (Network News Transport Protocol) 119
SNMP (Simple Network Management Protocol) 161
SNMP trap 162
PPTP (Point-to-Point Tunneling Protocol) 1723
8.3.3 Configuring Servers Behind SUA (Example)
Let's say you want to assign ports 21-25 to one FTP, Telnet and SMTP server (A in the example), port 80 to
another (B in the example) and assign a default server IP address of 192.168.1.35 to a third (C in the
example). You assign the LAN IP addresses and the ISP assigns the WAN IP address. The NAT network
appears as a single host on the Internet.
Figure 8-3 Multiple Servers Behind NAT Example
IP address
assigned by ISP.