Example 4: Nat Unfriendly Application Programs; Figure 342 Example 3: Menu 15.2; Figure 343 Nat Example 4 - ZyXEL Communications ZYWALL 2 PLUS User Manual

Figure 342 Example 3: Menu 15.2.

35.4.4 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 343 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-One-to-One
mapping types.
ZyWALL 2 Plus User's Guide
Menu 15.2 - NAT Server Setup
Default Server: 0.0.0.0
Rule Act. Start Port
------------------------------------------------------
001 Yes 80
002 Yes 25
003 No 0
004 No 0
005 No 0
006 No 0
007 No 0
008 No 0
009 No 0
010 No 0
Select Command= None
Press ENTER to Confirm or ESC to Cancel:
Chapter 35 Network Address Translation (NAT)
End Port IP Address
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
Select Rule= N/A
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