Few years ago, I had created one SNMP Poller tool using perl and snmp utilites that can poll OID informations from any network devices, which is kind of passive monitoring mechanism.
Thought to make it Opensource under GNU GPL.
The details of the utility with its usage can be found here, if anyone is interested to use it.
Long ago, while working in one of the previous organization, there were lots of components like services and servers running in production environment. I had deployed all products one by one from scratch and the count kept on increasing. There were components like PLM Servers, DB Server, License Mgmt, internal portal, Cotainer based virtualization system and a lots.
But there was no proper tools to monitor all the components at a time. As the count kept increasing , it becomes difficult to keep an eye on UP/DOWN time of all.
So I decided to deploy Nagios Monitoring system in the Data Center and developed many plugins to use.
I have opensourced few of the plugins, which I thought can help other people in world, those may facing these kind of challenges.
Also I posted them on Nagios Exchange on 4 years ago and now they are huge success. They each are downloaded 50k+ times and I received many thanks from many people from around the world and feel happy.
They can be found from here: https://exchange.nagios.org/directory/Owner/divyaimca/1
When ever we connect to another host with ssh client, it asks the user to add the public key of the remote host in the ~/.ssh/known_hosts file of that user. This is by default enabled by “StrictHostKeyChecking yes” which can be altered to no in /etc/ssh/ssh_config file.
But sometimes what happened, the host name remain same, but the key value might have been changed, due to some reason like : may be a new system with same host name OR the system may be compromised OR any other reason, the error will come as the fingerprint will mismatch:
Offending key for IP in ~/.ssh/known_hosts:n
Where ‘n’ is the line number in that file.
So in this case manually open the ~/.ssh/known_hosts and remove the line number “n”.
Or a simply perl pie will search and replace the line with an empty.
perl -pi -e ‘s/\Q$_// if ($. == n);’ ~/.ssh/known_hosts