Support FAQ

How do I set up Serial Port Cascading/Clustering?

Cascaded Ports enables you to cluster distributed console servers so a large number of serial ports (up to 1000) can be configured and accessed through one IP address and managed through the one Management Console. One console server, the Master, controls other console servers as Slave units and all the serial ports on the Slave units appear as if they are part of the Master.

Opengear's clustering connects each Slave to the Master with an SSH connection. This is done using public key authentication so the Master can access each Slave using the SSH key pair (rather than using passwords).This ensures secure authenticated communications between Master and Slaves enabling the Slave console server units to be distributed locally on a LAN or remotely around the world. To set up public key authentication you must:

generate the RSA or DSA key pair each new Slave-Master connection
upload the Public and Private Keys into the Master console server
register the Public Key as an Authorized Key on the Slave
fingerprint each new Slave-Master connection

For more information on generating your RSA or DSA key pair and uploading refer:
faq293 - Generating and uploading SSH keys under Linux or
faq297 - Generating and uploading SSH keys under Window.

To establish the fingerprint you first log in the Master server as root and establish an SSH connection to the Slave remote host (# ssh remhost). The Slave will receive a fingerprint from the Master which will be used to validate all future connections. For more details on fingerprinting refer Chapter 15.6 of the User Manual.

You can now begin setting up the Slaves and configuring Slave serial ports from the Master console server:

Simply select Serial & Network: Cascaded Ports on the Master's Management Console and Add Slave
Enter the remote IP Address (or DNS Name) for the new Slave console server along with a brief Description and a short Label
Enter the full number of serial ports on the Slave unit in Number of Ports and click Apply. This will establish the SSH tunnel between the Master and the new Slave

The Serial & Network: Cascaded Ports menu displays all the slaves and the port numbers that have been allocated on the Master. If the Master console server has 16 ports of its own then ports 1-16 are pre- allocated to the Master, so the first Slave added will be assigned port number 17 onwards and these ports can be configured and accessed as if they were the Master's ports.

For further details refer faq296 - What services in the Slave does the Master control when I cascade?