Hi, My name is Eric Moyers. I am a Network Support Engineer in the Cisco Small Business Support Center.
To create a 1 to 1 NAT define internal and external IP address ranges of equal length. Once the relationship is defined, the device with the first internal IP address is accessible at the first IP address in the external IP address range, and so forth.
For example, you have a Local Area Network (LAN) for which the ISP has assigned the IP address range of 209.19.28.16 to 209.19.28.31, with 209.19.28.16 used as the Wide Area Network (WAN) or NAT public IP address of the Router.
The address range of 192.168.168.1 to 192.168.168.255 is used for the devices on the LAN. With One-to-One NAT, the devices with the internal IP addresses of 192.168.168.2 to 192.168.168.15 may be accessed at the corresponding external IP addresses.
NOTE: The Router’s WAN IP address should not be included in the range you specify.
To setup one to one NAT do the following:
One-to-One NAT Select “Enable” to use the One-to-One NAT function.
Add Range
Private Range Begin Enter the starting IP address of the internal IP address range. This is the IP address of the first device that can be accessed from the Internet.
Public Range Begin Enter the starting IP address of the public IP address range. This IP address is provided by the ISP. (Do not include the Router’s WAN IP Address.)
Range Length Enter the number of IP addresses in the range. The range length cannot exceed the number of valid IP addresses. To map a single address, enter 1.
Click Add to List, and configure as many entries as you would like, up to a maximum of ten. To delete an entry, select it and click “Delete selected range”.
NOTE: One-to-One NAT affects how the firewall functions work. Access to LAN devices from the Internet is allowed unless additional Deny access rules are configured on the Firewall > Access Rules screen.
Click “Save Settings” to save your changes, or click “Cancel Changes” to undo them
If you have any issues with these instructions or require any additional help please call into our Small Business Support Center and any of our answering agents will be glad to assist you further.
The toll-free numbers to contact the support center can be found here :
http://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html
Please note that prior to calling, we recommend registering on the Cisco.com, and have the serial number of your device at hand, in order to facilitate the creation of a service request ticket.
Eric Moyers
Cisco Network Support Engineer
1-866-606-1866
