LAST MODIFIED DATE: September 13, 2007

VERSION: This applies to Exceed versions 9.0, 9.0+

PROBLEM:

How does Exceed V9.0 work with NAT and VPN?

Exceed version 9.0 now supports network connections that feature a VPN or NAT device where the "last remote translated" IP address for the client PC is not the same as the unique IP address assigned to that PC.

SOLUTION:

This feature of Exceed is called IP Discovery.

IP Discovery supports multiple connections involving a network address translation (NAT) device or virtual private network (VPN) software. Exceed ensures that X applications from remote hosts reach the client PC.

IPDisCov Daemon:

IPDisCov is a daemon on the remote UNIX host running X applications. By default, it listens on port 80 using HTTP. You can start IPDisCov on the UNIX host using the following command:

./IPDisCov -p listen_port_number

where listen_port_number is a port other than default 80.

Use a browser to connect to the host and if the browser displays the host IP address correctly, then it means that the IPDisCov was started and is working.

Note: Only the root user has the authority to run the daemon on the UNIX host.

IPDisCov daemon is available for AIX, HP, Linux and Solaris.

Using IP Discovery:

The IP Discovery files are available on the Exceed CD under \Extras\ExceedUnixVPN+NATSupport directory.

To use Exceed in XDMCP mode or to use Xstart to start an X application on a UNIX host, Exceed and Xstart must construct the DISPLAY environment variable for the X application to display on the client PC. However, there may be VPN software that does not register the host IP address with the Windows system (to find out if this is so, use the DOS utility ipconfig to display the network settings). In this case, the only way for Exceed and Xstart to communicate with the remote host is by means of IP Discovery.

Note: The environment variable DISPLAY tells the computer on which machine to display the X application..

To configure Exceed to use IP Discovery:

1. On the UNIX host, run ./IPDisCov -p listen_port_number. If necessary, specify another port number other than default port 80.
2. Use a browser to connect to IPDisCov and verify that the browser displays the correct IP address.
3. Open Xconfig. On the Communication page, select IP Discovery. Type the Server Address (the IP address where IPDisCov is running) and type the Port Number which IPDisCov is monitoring (if it is not the default 80).
4. Click Validate and Apply Changes.

For Exceed XDMCP startup modes:

1. On the Xconfig Communication page, select any XDMCP mode. Click Configure. The XDCMP Startup Modes dialog box opens.
2. In the Network Adapter(s) area, select Network Interface and click Settings. The Network Interfaces dialog box opens.
3. There should be an entry in the list with the interface name “From IP Discovery Server”. The entry indicates the IP address (provided by the IPDisCov daemon) that Exceed uses to determine the DISPLAY environment variable. Select the entry and click OK.
4. Click Validate and Apply Changes.

Note: If IP Discovery is enabled in Xconfig, you can select a interface name and IP address in the Network Interfaces dialog box when Exceed connects to the remote host.

For Xstart:

1. Open Xstart. In the Settings area, click Other. The Other Settings dialog box opens.
2. On the Connection page, select Interfaces and click Settings. The Network Interfaces dialog box opens.
3. There should be an entry in the list with the interface name “From IP Discovery Server”. The entry indicates the IP address (provided by the IPDisCov daemon) that Xstart uses to determine the DISPLAY environment variable. Select the entry and click OK.

Note: If IP Discovery is enabled in Xconfig, you can select a interface name and IP address in the Network Interfaces dialog box opens when Exceed connects to the remote host.