ZyXEL Communications ZyXEL ZyWALL 5 - Manual (Page 460)

ZyWALL 5 User’s Guide
Chapter 33 Network Address Translation (NAT) 459
Figure 272 Example 3: Menu 15.2
33.4.4 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-One-to-One mapping as port numbers do not change for
Many-One-to-One (and One-to-One) NAT mapping types. The following figure illustrates
this.
Figure 273 NAT Example 4
Note: 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-
One-to-One mapping types.
Follow the steps outlined in example 3 above to configure these two menus as follows.
Menu 15.2 - NAT Server Setup
Default Server: 0.0.0.0
Rule Act. Start Port End Port IP Address
------------------------------------------------------
001 Yes 80 80 192.168.1.21
002 Yes 25 25 192.168.1.20
003 No 0 0 0.0.0.0
004 No 0 0 0.0.0.0
005 No 0 0 0.0.0.0
006 No 0 0 0.0.0.0
007 No 0 0 0.0.0.0
008 No 0 0 0.0.0.0
009 No 0 0 0.0.0.0
010 No 0 0 0.0.0.0
Select Command= None Select Rule= N/A
Press ENTER to Confirm or ESC to Cancel: