Cisco ROUTER-SDM-CD User Manual page 864

More About NAT
Scenario 2
Translate from Interface Fields
Static/Dynamic IP Address
Static 10.12.12.35 (host)
Scenario 3
Translate from... fields
Static/Dynamic IP Address
Static 10.12.12.3
Cisco Router and Security Device Manager 2.5 User's Guide
40-14
You need to map each IP address in a network to a unique public IP address, and
you do not want to create a separate rule for each mapping. The source network
number is 10.l2.12.0, and the target network is 172.17.4.0. However, in this
scenario, it is not necessary to know the source or target network numbers. It is
sufficient to enter host addresses and a network mask.
The following table shows how the fields in the Add Address Translation Rule
window would be used.
Net Mask
255.255.255.0
Result
NAT derives the "Translate from" network address from the host IP address and
the subnet mask. NAT derives the "Translate to" network address from the the net
mask entered in the "Translate from" fields, and the "Translate to" IP address. The
source IP address in any packet leaving the original network is translated to an
address in the 172.17.4.0 network.
You want to use the same global IP address for several hosts on the trusted
network. Inbound traffic will contain a different port number based on the
destination host.
The following table shows how the fields in the Add Address Translation Rule
window would be used.
Net Mask
Leave blank
Translate to Interface Fields
IP Address
172.17.4.8 (host)
Translate to... fields
IP Address Redirect Port
172.17.4.8 UDP
Original Port 137
Translated Port 139
Chapter 40 More About....
Redirect Port
Leave unchecked.
OL-4015-12