ZyXEL Router Prestige 334 User Manual

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Chapter 25 Network Address Translation (NAT) 240
Figure 115   Menu 15.1.255 SUA Address Mapping Rules 
The following table explains the fields in this menu. 
25.3.1.1  User-Defined Address Mapping Sets
Now let’s look at option 1 in menu 15.1. Enter 1 to bring up this menu. We’ll just look at the 
differences from the previous menu. Note the extra Action and Select Rule fields mean you 
can configure rules in this screen. Note also that the [?] in the Set Name field means that...

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Figure 116   Menu 15.1.1 First Set
25.3.1.2  Ordering Your Rules
Ordering your rules is important because the Prestige applies the rules in the order that you 
specify. When a rule matches the current packet, the Prestige takes the corresponding action 
and the remaining rules are ignored. If there are any empty rules before your new configured 
rule, your configured rule will be pushed up by that number of empty rules. For...

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Now if you delete rule 4, rules 5 to 7 will be pushed up by 1 rule, so as old rule 5 becomes rule 
4, old rule 6 becomes rule 5 and old rule 7 becomes rule 6. 
Selecting Edit in the Action field and then selecting a rule brings up the following menu, 
Menu 15.1.1.1
 - Address Mapping Rule in which you can edit an individual rule and 
configure the Ty p e, Local and Global Start/End IPs.
Table 82   Menu 15.1.1 First Set...

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Figure 117   Menu 15.1.1.1 Editing/Configuring an Individual Rule in a Set
The following table explains the fields in this menu.
25.4  Configuring a Server behind NAT
Follow these steps to configure a server behind NAT:
1Enter 15 in the main menu to go to Menu 15 - NAT Setup.
2Enter 2 to display Menu 15.2 - NAT Server Setup as shown next.
Menu 15.1.1.1 Address Mapping Rule
     Type= One-to-One
     Local IP:
       Start=...

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Figure 118   Menu 15.2.1 NAT Server Setup
3Enter a port number in an unused Star t Po rt No field. To forward only one port, enter it 
again in the End Port No field. To specify a range of ports, enter the last port to be 
forwarded in the End Port No field. 
4Enter the inside IP address of the server in the IP Address field. In the following figure, 
you have a computer acting as an FTP, Telnet and SMTP server (ports 21, 23 and...

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25.5.1  Example 1: Internet Access Only
In the following Internet access example, you only need one rule where the ILAs (Inside Local 
Addresses) of computers A through D map to one dynamic IGA (Inside Global Address) 
assigned by your ISP. 
Figure 120   NAT Example 1
Figure 121    Menu 4 Internet Access & NAT Example
From menu 4, choose the SUA Only option from the Network Address Translation field. 
This is the Many-to-One...

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Figure 122   NAT Example 2
In this case, you do exactly as above (use the convenient pre-configured SUA Only set) and 
also go to menu 15.2 to specify the Inside Server behind the NAT as shown in the next figure.
Figure 123   Menu 15.2.1 Specifying an Inside Server
25.5.3  Example 3: Multiple Public IP Addresses With Inside Servers
In this example, there are 3 IGAs from our ISP. There are many departments but two have 
their own...

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4You also map your third IGA to the web server and mail server on the LAN. Type 
Server allows you to specify multiple servers, of different types, to other computers 
behind NAT on the LAN.
The example situation looks somewhat like this:
Figure 124   NAT Example 3
1In this case you need to configure Address Mapping Set 1 from Menu 15.1 - Address 
Mapping Sets. Therefore you must choose the Full Feature option from the Network...

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Figure 125   NAT Example 3: Menu 11.3
The following figures show how to configure the first rule.
Menu 11.3 - Remote Node Network Layer Options
           IP Address Assignment= Dynamic
           IP Address= N/A
           IP Subnet Mask= N/A
           Gateway IP Addr= N/A
           Network Address Translation = Full Feature
           Metric= 1
           Private= N/A
           RIP Direction= None
             Version= N/A...

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Figure 126   Example 3: Menu 15.1.1.1 
Figure 127   Example 3: Final Menu 15.1.1
Now configure the IGA3 to map to our web server and mail server on the LAN. 
8Enter 15 from the main menu.
9Enter 2 in Menu 15 - NAT Setup.
10Enter 1 in Menu 15.2 - NAT Server Setup to see the following menu. Configure it as 
shown. 
Menu 15.1.1.1 Address Mapping Rule
     Type= One-to-One
     Local IP:
       Start= 192.168.1.10
       End  = N/A...