16CPS Installer/User Guide

The PPP dial-in may be used to access a remote CPS appliance that does not warrant a WAN (Wide Area Network) link to the Ethernet interface. In this case, the PPP connection allows a remote PC with Telnet capability to dial the CPS appliance and then establish a Telnet connection to a port.

The PPP dial-in may also be used to access a subnet containing remote CPS devices in the event of a WAN link failure. In this case, the PPP provides an alternate path to one or more remote

CPS devices.

Once the PPP connection is established, you must launch an application that connects to the CPS appliance or to one of its ports. The PPP connection is only a communications interface to the CPS appliance.

The CPS appliance implements a PPP server that uses CHAP (Challenge Authentication Protocol). Passwords are not accepted in the clear on PPP connections.

The authentication of PPP dial-in connections is not affected by enabling/disabling the server-level CLI port authentication parameter. See Preemption on page 21 for more information.

To enable or disable a PPP server on the serial CLI port:

1.To enable a PPP server on the serial CLI port, issue a Show Server CLI command to ensure that a serial CLI port has been defined.

SHOW SERVER CLI

2.Issue a Server PPP command with the Enable parameter.

SERVER PPP ENABLE LOCALIP=<local_ip> REMOTEIP=<rem_ip> [MASK=<subnet>]

You must specify local and remote IP addresses to be used for the CPS appliance and client ends of the PPP connection respectively. You are prompted to confirm or cancel the changes. Enter Y to confirm or N to cancel.

3.To disable a PPP server, issue a Server PPP command with the Disable parameter.

SERVER PPP DISABLE

For more information, see Show Server CLI command on page 65 and Server PPP command on page 54.

To display PPP configuration information:

Issue a Show Server PPP command.

SHOW SERVER PPP

For more information, see Show Server PPP command on page 66.

Connecting to devices using SSH

The CPS serial over IP network appliance supports version 2 of the SSH protocol (SSH2). The CPS SSH server operates on the standard SSH port 22. The shell for this connection provides a CLI prompt as if you had established a Telnet connection on port 23. The shell request for this connection is for CLI access.

Additional CPS SSH servers operate on TCP ports that are numbered with values 100 greater than the standard 30xx Telnet ports for the CPS appliance. For example, if port 7 is configured for