Example 4: Nat Unfriendly Application Programs; Figure 112 Example 3: Menu 15.2.1; Figure 113 Nat Example 4 - ZyXEL Communications ADSL2+ Ethernet/USB Gateway 660RU-Tx Series User Manual

Prestige 660RU-Tx Series User's Guide

Figure 112 Example 3: Menu 15.2.1

21.5.4 Example 4: NAT Unfriendly Application Programs

Some applications do not support NAT Mapping using TCP or UDP port address translation.
In this case it is better to use Many-to-Many No Overload mapping as port numbers do not
change for Many-to-Many No Overload (and One-to-One) NAT mapping types. The
following figure illustrates this.

Figure 113 NAT Example 4

Other applications such as some gaming programs are NAT unfriendly because they embed
addressing information in the data stream. These applications won't work through NAT even
when using One-to-One and Many-to-Many No Overload mapping types.
Follow the steps outlined in example 3 to configure these two menus as follows.
175
Menu 15.2.1 - NAT Server Setup
Rule Start Port No.
---------------------------------------------------
1. Default
2. 80
3. 25
4. 0
5. 0
6. 0
7. 0
8. 0
9. 0
10. 0
11. 0
12. 0
Press ENTER to Confirm or ESC to Cancel:
End Port No. IP Address
Default 0.0.0.0
80 192.168.1.21
25 192.168.1.20
0 0.0.0.0
0 0.0.0.0
0 0.0.0.0
0 0.0.0.0
0 0.0.0.0
0 0.0.0.0
0 0.0.0.0
0 0.0.0.0
0 0.0.0.0
Chapter 21 Network Address Translation (NAT)