ZyXEL Communications ZyWALL 10, User Manual

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ZyWALL 10 Internet Security Gateway
6-20 NAT
6.4.4 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-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 6-21 NAT Example 4
Other applications, e.g., gaming programs are NAT unfriendly because they embed
addressing information in the data stream. These applications still 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 above to configure these two menus as follows.