Configuring N:N mapping requires actually very little information. Since a LAN can be coupled with numerous other networks via N:N, a source IP range can be translated in different ways depending on the destination. The NAT table contains a maximum of 64 entries containing the following information:
- Index: Unique index for the entry
- Source address: IP address of the computer or network that is to receive an alternative IP address.
- Source mask: Netmask of the source range.
- Destination station: Name of the remote device that can be used to access the remote network.
- Mapped network: IP address or address range that should be used for the translation.
For the new network address, the same netmask is taken as used by the source address. The following applies with the assignment of source and mapping addresses:
- When translating individual addresses, source and mapping can be assigned in any way. For example, the server in the LAN with the IP address 10.1.1.99 can be assigned the mapping address 192.168.1.88.
- When entire address ranges are translated, the computer-related part of the IP address is used directly and only the network-related part of the mapping address is appended. When assigning 10.0.0.0/255.255.255.0 to 192.168.1.0, the server in the LAN with the IP address 10.1.1.99 is necessarily assigned with the mapping address 192.168.1.99.
Note: The address range for translation must be at least as large as the source address range.
Note: Please note that the N:N mapping function is only effective when the firewall is activated.