Cisco ONS 15454 Series Multiservice Provisioning Platforms

Use NAT to Hide the Real IP Address of CTC to Establish a Session with ONS 15454

Document ID: 65122

Updated: Jan 09, 2006



This document provides a sample configuration for Network Address Translation (NAT) to establish a session between Cisco Transport Controller (CTC) and ONS 15454. The configuration hides the real IP address of CTC through NAT when CTC resides inside the firewall.

Note: For this procedure to work, you must ensure that the ports are not blocked or filtered.



Before you attempt this configuration, ensure that you have knowledge of these topics:

  • Cisco ONS 15454

  • Cisco Routers that support NAT

Components Used

The information in this document is based on these software and hardware versions:

  • Cisco ONS 15454 version 5.0 and later

  • Cisco IOS® Software Release 12.1(11) and later

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.


For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Background Information


The topology consists of these elements:

  • One Cisco ONS 15454

  • One PC

  • Two Cisco 2600 series routers

Cisco ONS 15454 resides in the external network, and acts as the server. The PC resides in the internal network, and serves as the CTC client.


In this section, you are presented with the information to configure the features described in this document.

Note: To find additional information on the commands used in this document, use the Command Lookup Tool (registered customers only) .

Network Diagram

This document uses this network setup:



This document uses these configurations:

  • Cisco ONS 15454

  • PC

  • Cisco 2600 series routers

Cisco ONS 15454 Configuration is the IP address of the ONS 15454 (see arrow A in Figure 2), and represents the default router (see arrow B in Figure 2).

Figure 2 – ONS 15454 Configuration


PC Configuration is the IP address of the PC (see arrow A in Figure 3), and represents the default gateway (see arrow B in Figure 3). NAT translates the IP address to for security reasons. The Cisco 2600 series router provides the necessary support for NAT and routing.

Figure 3 – PC Configuration


Router Configuration

Complete these steps to configure NAT support on the routers:

  1. Configure the outside interface.

    interface Ethernet1/1
     ip address
     ip nat outside
  2. Configure the inside interface where the PC resides.

    interface Ethernet1/2
     ip address
     ip nat inside
  3. Configure static NAT.

    ip nat inside source static

    The configuration converts the IP address (inside local) (see arrow B in Figure 4) to (inside global) (see arrow A in Figure 4).

  4. Issue the show ip nat translations command on the router.

    Figure 4 – IP NAT Translations



This section provides information you can use to confirm your configuration is working properly.

Verification Procedure

Complete these steps:

  1. Run Microsoft Internet Explorer.

  2. Type in the Address bar of the browser window, and press ENTER.

    The CTC Login window appears.

  3. Type your User Name and Password to log in.

    CTC client must successfully establish a session with the ONS 15454.


This section provides information you can use to troubleshoot your configuration.

Troubleshooting Commands

Certain show commands are supported by the Output Interpreter Tool (registered customers only) , which allows you to view an analysis of show command output.

Note: Before issuing debug commands, refer to Important Information on Debug Commands.

  • debug ip nat detailed—turns on the IP NAT detailed trace.

The output of the debug ip nat command indicates the address translations. For example, NAT translates to when CTC sends data to ONS 15454 (see arrow A in Figure 5). Similarly, NAT translates to when CTC receives data from ONS 15454 (see arrow B in Figure 5).

Figure 5 – Debug IP NAT Detailed


Related Information

Updated: Jan 09, 2006
Document ID: 65122