Discovery - how to find the IP Ranges of network segments

[justx]

Hello Community,

What is the best practice to find the IP Ranges for an environment which I doesn't know the ranges ?

Case scenario:

I have 4 different mid servers and I was provided with CLASS B network addresses.
Running IP Addresses schedules I found the class C network addresses.
Now what is the best practice to find for each MID Server IP Ranges?

At the moment I am running each class C network address on each mid server and analyzing the situation (how many CIs are added, which credentials works and etc)

Is there any other way to understand which IP Range is supposed to be on the relevant mid server ?

[Alberto Consonn]

Hi,

check the below documentation, it will clarify the best practice:

Discovery IP address configuration

If I have answered your question, please mark my response as correct so that others with the same question in the future can find it quickly and that it gets removed from the Unanswered list.

Thank you

Cheers
Alberto

[Deepak Ingale1]

Unless and until your network team has blocking IP ranges per MID Server, you can discovery any IP address range from any MID Server ( Provided Firewalls are opened )

Now, what issue you are getting? 

Best practice is to discover the devices by configuring smaller IP address range and across distributed schedules.

Note: Please mark reply as correct / helpful if it answers your question

[justx]

Hello Deepak Ingale,

"Best practice is to discover the devices by configuring smaller IP address range and across distributed schedules."

This is what I am doing at the moment.
In order to find the ip ranges for each mid. The mid which answered(giving me some CIs) is probably the right mid server for specific IP Range.

Mostly issues are that I do not have credentials/RPC unavailable or firewall.

[doug_schulze · Accepted solution]

Networks discovery to the rescue

this feature is built in for just this case.  You will create a networks discovery schedule and feed it your core/peer routers and we will query the device to learn the subnets that it manages and who they peer with then go query those network devices for the same.  As we basically spider around the network we will fill the IP networks table with the results where you can build range sets to include in a proper configuration items discovery to find what's in all those networks.

For this to work be sure to have all appropriate community strings and ensure your mid server(s) IP addresses are in identified ACLs so they can make the necessary SNMP queries to the network targets.