ZyXEL ARMOR Z2 User Guide - Page 85

Network Address Translation, 10.1 Overview, 10.2 What You Can Do, A: 192.168.1.33

Page 85 highlights

CHAPTER 10 Network Address Translation 10.1 Overview This chapter discusses how to configure NAT on the NBG6615. NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP address of a host in a packet. For example, the source address of an outgoing packet, used within one network is changed to a different IP address known within another network. Each packet has two addresses - a source address and a destination address. For outgoing packets, NAT maps private (local) IP addresses to globally unique ones required for communication with hosts on other networks. It replaces the original IP source address in each packet and then forwards it to the Internet. The NBG6615 keeps track of the original addresses and port numbers so incoming reply packets can have their original values restored. The following figure illustrates this. Figure 55 NAT Example A: 192.168.1.33 FTP, Telnet, SNMP Ports 21 to 25 LAN WAN B: 192.168.1.34 Port 80 192.168.1.1 C: 192.168.1.35 IP address assigned by ISP For more information on IP address translation, refer to RFC 1631, The IP Network Address Translator (NAT). Note: You must create a firewall rule in addition to setting up NAT, to allow traffic from the WAN to be forwarded through the NBG6615. 10.2 What You Can Do • Use the General screen to enable NAT and set a default server (Section 10.3 on page 87). NBG6615's User's Guide 85

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NBG6615’s User’s Guide
85
C
HAPTER
10
Network Address Translation
10.1
Overview
This chapter discusses how to configure NAT on the NBG6615.
NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP address of a host in a
packet. For example, the source address of an outgoing packet, used within one network is changed to
a different IP address known within another network.
Each packet has two addresses – a source address and a destination address. For outgoing packets,
NAT maps private (local) IP addresses to globally unique ones required for communication with hosts on
other networks. It replaces the original IP source address in each packet and then forwards it to the
Internet. The NBG6615 keeps track of the original addresses and port numbers so incoming reply packets
can have their original values restored. The following figure illustrates this.
Figure 55
NAT Example
For more information on IP address translation, refer to
RFC 1631
,
The IP Network Address Translator
(NAT)
.
Note: You must create a firewall rule in addition to setting up NAT, to allow traffic from the
WAN to be forwarded through the NBG6615.
10.2
What You Can Do
Use the
General
screen to enable NAT and set a default server (
Section 10.3 on page 87
).
A: 192.168.1.33
B: 192.168.1.34
C: 192.168.1.35
IP address
192.168.1.1
WAN
LAN
assigned by ISP
FTP, Telnet, SNMP
Port 80
Ports 21 to 25