Secure Shell (SSH) Check Guidelines

Introduction

SSH Secure Shell allows secure network services over an insecure network, such as the Internet. With SSH, ActiveXperts Network Monitor can login onto a remote machine running the SSH daemon, and execute a command or shell script. ActiveXperts Network Monitor requires the output (i.e. StdOut) to be formatted according to the following syntax:

[ SUCCESS | ERROR | UNCERTAIN]: { <explanation> } { DATA:<value>}

The <explanation> will be shown in the 'Last Response' column in the Manager application. The <value> field will be shown in the 'Data' column in the Manager application. Samples:

ERROR: Free Disk space is less than 40 GB DATA:34

SUCCESS: Daemon 'LPD' is running

An SSH Shell Script check requires the following parameters:


Private Key File format

To logon using a Private Key File, make sure that your key file is in PuTTY compatible format. PuTTY is a free and open-source terminal emulator, and very popular under Windows.

In order to use Private Key File authentication with ActiveXperts, make sure you have generated your public/private key pair under Linux, and copy the private key file to a Windows machine, like this:

Now, you need to convert your private key file (e.g. 'id_rsa') to a PuTTY compatible file (e.g. 'id_rsa.ppk'):


SSH login takes long

If connecting to a host with SSH takes much longer than reasonable, it is likely that reverse DNS lookup by the SSH daemon is the reason for that.

There is a setting in OpenSSH that controls whether SSHd should not only resolve remote host names but also check whether the resolved host names map back to remote IPs. That setting is enabled by default in OpenSSH.

There are two way to fix it (on the SSH host):


Network Monitor SSH checks

Please click here for more information on Network Monitor SSH checks.


Samples

Please click here for more information on Network Monitor SSH samples.