Splunk Search

Splunk Regex - Works in regex101 but not Splunk

JacobCarrell
Explorer

I've got a regex that's working in Regex101's editor, but when I paste it into Splunk I get garbage or no results:
Regex:

^(?:[^ \n]* ){5}\[(?P<username>\w+)(?:\].*\])(?P<IP>[^:]+)

Sample entries:
Oct 24 18:43:57 openvpn[36372]: 66.103.224.123:59349 [username] Peer Connection Initiated with [AF_INET]66.103.224.123:59349
Oct 24 18:28:54 openvpn[21337]: 66.103.224.123:50873 [username] Peer Connection Initiated with [AF_INET]66.103.224.123:50873

URL:
https://regex101.com/r/by1mOW/7

0 Karma
1 Solution

gcusello
SplunkTrust
SplunkTrust

Hi
why you say that doesn't run on Splunk?
I tried this

index=_internal  
|head 1 
| eval ppp="Oct 24 18:43:57 openvpn[36372]: 66.103.224.123:59349 [username] Peer Connection Initiated with [AF_INET]66.103.224.123:59349" 
| rex field=ppp "^(?:[^ \n]* ){5}\[(?P<username>\w+)(?:\].*\])(?P<IP>[^:]+)" 
| table username IP

And I have

username    IP
username    66.103.224.123

Bye.
Giuseppe

View solution in original post

gcusello
SplunkTrust
SplunkTrust

Hi
why you say that doesn't run on Splunk?
I tried this

index=_internal  
|head 1 
| eval ppp="Oct 24 18:43:57 openvpn[36372]: 66.103.224.123:59349 [username] Peer Connection Initiated with [AF_INET]66.103.224.123:59349" 
| rex field=ppp "^(?:[^ \n]* ){5}\[(?P<username>\w+)(?:\].*\])(?P<IP>[^:]+)" 
| table username IP

And I have

username    IP
username    66.103.224.123

Bye.
Giuseppe

JacobCarrell
Explorer

Thanks, I didn't know you could do this. It turns out I'm using an app that provides predefined sourcetypes. I ran out of oomph last night after rewriting the regex to grab the IP from the first IP and STILL getting the same results, so somewhere in one of my props.conf or transforms.conf is a bad regex. I'll have to track it down tonight.

For the record, this is syslogs from PFSense.

JacobCarrell
Explorer

Forgot to add, Here's what Splunk captures for the IP:
Initiated with [AF_INET]66.103.224.123

0 Karma
Get Updates on the Splunk Community!

Your Guide to Splunk Digital Experience Monitoring

A flawless digital experience isn't just an advantage, it's key to customer loyalty and business success. But ...

Data Management Digest – November 2025

  Welcome to the inaugural edition of Data Management Digest! As your trusted partner in data innovation, the ...

Upcoming Webinar: Unmasking Insider Threats with Slunk Enterprise Security’s UEBA

Join us on Wed, Dec 10. at 10AM PST / 1PM EST for a live webinar and demo with Splunk experts! Discover how ...