Telnet and SSH Tools from OneClick failed - Connection closed

Products

• CA Spectrum
• DX NetOps

Issue/Introduction

The Telnet and SSH (Secure Shell) Tools no longer work from the OneClick Console after migrated the Spectrum to a new Linux machine.

Directly from any of our SpectroServer via Linux bash I can reach any device via SSH or Telnet without any problem.

In the case of Telnet - there is just "Connection to x.x.x.x closed."  message, without user prompt.

In the case of SSH - there is a login and password prompt, after typing the right data, the message "Connection to x.x.x.x closed." is displayed.

Environment

Release : 20.2

Component : SPCOCK: Spectrum OneClick

Cause

The firewall on the SpectroSERVER machine was denying the connection on port 31415 (Telnetd) originated from the OneClick server.

a) Is the Telnetd process running on the SpectroSERVER machine?
$ ps -ef | grep Telnetd

b) Is the Telnetd listening on port 31415 on the SpectroSERVER machine?
$ netstat -ano -p | grep 31415

Note that the Telnetd PID (from item a) 6828 matches with the PID in netstat (6282/telnetd)

c) From the OneClick server, are you able to establish a telnet connection to the SpectroSERVER machine on port 31415?
$ telnet SpectroSERVER 31415
When the SSH Tools (in OneClick Console) establishes the connection with the device/host, you can see that the OneClick server (OC_IP) established the connection with the SpectroSERVER (SS_IP) on port 31415.

Resolution

Allow connection on port 31415 on the firewall.

# firewall-cmd --permanent --add-port=31415/tcp
# firewall-cmd --reload

Additional Information

About the Telnet/Mindterm option is no longer appearing in Debug Console list.

In the Debug Console, if the ssh client is not opened for any device before, then "Mindterm" and "Telnet" do not appear in Debug Control TAB.

So, we open an ssh client once for any device to see the option in Debug Control.