In order to discover details of a device / machine / server, does the discovery tool perform a task equivalent to logging into the device to obtain relevant configuration details of the device?

[YASHIK]

In order to discover details of a certain device / machine / server, does the discovery tool literally have to perform a task equivalent to logging into the device using IP Address and credentials to get relevant configuration details of the machine ? I have read contents relating to discovery tool but i am not able to get this simple and yet vital detail. If someone can explain this to me in easy to understand words thanks

[justprashantkau]

Hi Yashik,

That's correct, once you run the quick discovery & schedule discovery you should get all the relevant information about any server, applications or application services. Let's understand with below points out there -

GAINING CREDENTIALS

#1 step in a ServiceNow Discovery implementation is gaining the credentials to run discovery on your network.  Discovery applications are invasive and powerful, they do scan and obtain information all about your company infrastructure.  This requires a lot of rights and access.

SETTING UP INITIAL DISCOVERY

I do not recommend just "turning on" ServiceNow Discovery when you get the credentials. Plan out what you want to discovery and test small range sets.

Some Setup Tasks I recommend

1. Buy Discovery
2. Activate Discovery Plugin
3. Setup Credentials
4. Setup Port Probes
5. Deploy Midservers to access network
6. Setup Discovery Schedule and Range Sets
7. Try small range set for testing

Understanding the discovery lifecycle is important to understanding how it works and what to do if it doesn't or if you want to change it.

Port Scan Phase

1. Discovery Schedule or Discover Now Runs
2. Shazzam (Port Probes) Run.  Checks for open ports for configured probes.  If no ports are open for configured probes, discovery stops.

Classification Phase

1. Depending on what ports were open on Port Scan Phase, Probes will run. For example: WMI.  If Windows WMI port was open, WMI Probe, Windows - Classify will run
2. Sensor will return results.  If there are bad credentials for for the Probe, discovery fails for this CI.
3. CI is given a class and classified.  

Identification Phase

1. If CI is Classified, Identify probes runs
2. It is determined to update or insert a new CI

Exploration Phase

1. All remaining probes run and sensors return results and update CI, related lists, and relationships.

VALIDATE RESULTS

Running a CMDB unchecked is not a good idea.  If you are using ServiceNow Discovery, you should run reports to determine if the CMDB is accurate.  Are you discovering the anticipated number of CIs?  Many factors can decide whether you are discovering too much or too little.

I suggest setting periodic meetings to check CMDB data for accuracy and eliminate duplicates.  One idea is to generate a monthly incident to make sure maintenance is completed.

I hope that's helpful to understand your points which you mentioned.

Thanks!