Splunk Search

How do I do a CIDR match with an inputlookup?

adepasquale
Path Finder

Hi All,

I have a lookup that currently works. I've set match_type to CIDR(netRange) in my transforms file and everything works when I pass it an IP address to find in the range.

However, I'm looking to use this lookup table without a search. So I went with the creating command inputlookup, but for the life of me, I cannot get a CIDR match to work. I want to pass it an IP, and have it find the matching CIDR notation in netRange.

Is there no way to do this with the inputlookup command — why is it not honoring my transform?

This works:

index="main" | eval cip="1.1.1.1" | lookup IP2ASN netRange AS cip

This does not work

|inputlookup IP2ASN where netRange=1.1.1.1
0 Karma
1 Solution

somesoni2
Revered Legend

Try this

| makeresults | eval cip="1.1.1.1" | lookup IP2ASN netRange AS cip

View solution in original post

somesoni2
Revered Legend

Try this

| makeresults | eval cip="1.1.1.1" | lookup IP2ASN netRange AS cip

adepasquale
Path Finder

Gold! thank you, and to be clear... I'm not actually issuing a search with "makeresults"?

0 Karma

somesoni2
Revered Legend

You're running a search command that generates a dummy row (not searching actual indexes). Technically it's still a search.

0 Karma

adepasquale
Path Finder

It'll do, thanks again.

0 Karma

Vijeta
Influencer

@adepasquale Try this-

|inputlookup IP2ASN  | where netRange="1.1.1.1"
0 Karma

adepasquale
Path Finder

This doesn't work either. netRange has values like 1.0.0.0/24, 1.0.1.0/24, 1.1.1.0/24, etc...

0 Karma
Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

How to find the worst searches in your Splunk environment and how to fix them

Everyone knows Splunk is a powerful platform for running searches and doing data analytics. Your ...

Share Your Feedback: On Admin Config Service (ACS)!

Help Us Build a Better Admin Config Service Experience (ACS)   We Want Your Feedback on Admin Config Service ...

Build the Future of Agentic AI: Join the Splunk Agentic Ops Hackathon

AI is changing how teams investigate incidents, detect threats, automate workflows, and build intelligent ...