Users Manual Part 2

Chapter 12 Network Address Translation (NAT)

NBG7510 User’s Guide

176

Figure 106 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 66 Services and Port Numbers

SERVICES PORT NUMBER

ECHO 7

FTP (File Transfer Protocol) 21

SMTP (Simple Mail Transfer Protocol) 25

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

PPTP (Point-to-Point Tunneling Protocol) 1723