Connecting via a Cisco Terminal Server

Connecting via a Cisco Terminal Server

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CatTools V3 supports a Cisco Terminal Server device type.

This device type is designed to enable CatTools to connect to devices physically connected to a terminal server type device via the console port. It should support authentication to both the terminal server device and to the device connected to it, or to just one or other of the devices. It should support either local or remote authentication. This type of connection is sometimes known as reverse telnet.

To set up a terminal server:

1.	add a new device to CatTools using the Cisco Terminal Server device type

2.	set the device Host Address to the correct IP address of the device

3.	set the Connect via to Direct connect

4.	set the authentication on this device to the passwords required when using a port of the terminal server

To use the terminal server to connect to a device make the following settings on the device that is attached to it:

1.	set the CatTools device type to the type that corresponds to the actual device type

2.	set the Connect via to connect via the terminal server device

3.	set the Method to telnet

4.	set the Port to the port on the terminal server the device is connected to. i.e. Async Port 1 = TCP port 2001

5.	set the authentication required to access the device itself

To run an activity on the device that is connected to the terminal server, just select the device itself.

When CatTools wants to connect to the device, it knows to connect to the terminal server first. It connects to the terminal server using the port that is defined to the device that is connected to via the terminal server. If any authentication is required to use the port, it uses the authentication details from the terminal server. After CatTools authenticates to the terminal server, it sends a CR to it to activate the port. It will then authenticate to the device behind the terminal server using the credentials set to that device.

There are several things to bear in mind when utilising a terminal server with CatTools.

1.	The connection is normally via a comm type port. The device may well be significantly slower to access from CatTools.

2.	The terminal server must be directly connected to by CatTools. CatTools does not support the use of a terminal server that has to be connected to via another device.

If you need to connect to the terminal server itself to say issue commands or back it up, define a separate device to CatTools using its normal device type, such as Cisco router general for a Cisco 2509 router. Set its device details up with the correct Host Address, connection method, and the like. Set the port to the normal connection method port, such as port 23 for telnet.

After disconnecting from a device on the terminal server, the port connection may be left open before timing out. The duration of the timeout depends on the settings on the device. Where the device requires authentication, and you try to reconnect to it before the port connection has timed out, CatTools may fail to connect with a message like "Did not receive VTY entry prompt ...". This happens because CatTools is set to send authentication to the device and the device does not require it as the port connection is still available. You can unset the authentication options for the device in CatTools, and it should then connect.

To help if this is a problem, you may want to set the exec timeout (Cisco router) value low to ensure the console connection does not stay up for long periods of time.