Splunk Search

Field Extraction (rex maybe?)

a_n
Path Finder

Hello All,

I am not good in Regular Expressions, I need you assist.

In my data, I have a field containing IPs and Ports but in specific sequence:

...some text ... SourceIP DestIP SrcPort DestPort ....some text...
between them there is one SPACE.
as an example:
message=...w 2-APIS 0-External-1 tcp 10.0.12.13 40.126.31.8 55373 443 msg=\"HTTS...

I need to extract fields for SrcIP, DestIP, SrcPort and DestPort.
when I use

 \b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b \b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b \d* \d*

OR

\b(?:[0-9]{1,3}\.){3}[0-9]{1,3} (?:[0-9]{1,3}\.){3}[0-9]{1,3}\b \d* \d*
I can grab the 2 IPs and ports  with spaces between them.
I am confused about how to assign each to a new field.
Can someone help?
Or do I have to use REX for search time extraction?
Even to use REX, I appreciate your advices.

Regards,

-Ali

Labels (2)
0 Karma
1 Solution

scelikok
SplunkTrust
SplunkTrust

Hi @a_n,

You should use captured group on regex. 

rex sample;

| rex field=message "\b(?<src_ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b \b(?<dest_ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b (?<src_port>\d*) (?<dest_port>\d*)"

props.conf extract

EXTRACT-fields = \b(?<src_ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b \b(?<dest_ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b (?<src_port>\d*) (?<dest_port>\d*)
If this reply helps you an upvote and "Accept as Solution" is appreciated.

View solution in original post

a_n
Path Finder

Thank you @scelikok 

Undersood.

 

0 Karma

gcusello
SplunkTrust
SplunkTrust

Hi @a_n,

please try this:

| rex "(?<src_ip>\d+\.\d+\.\d+\.\d+)\s+(?<dest_ip>\d+\.\d+\.\d+\.\d+)\s+(?<src_port>\d+)\s+(?<dest_port>\d+)"

that you can test at https://regex101.com/r/UTRazw/1

if you could share two or three full samples of your logs I could be more precise.

Ciao.

Giuseppe

a_n
Path Finder

@gcusello 

Thank you

0 Karma

a_n
Path Finder

Dears,
I used this:
(?<srcip>\d+\.\d+\.\d+\.\d+) (?<dstip>\d+\.\d+\.\d+\.\d+) (?<srcpt>\d+) (?<dstpt>\d+)

Seems ok, but does anyone have better idea?

0 Karma

scelikok
SplunkTrust
SplunkTrust

Hi @a_n,

You should use captured group on regex. 

rex sample;

| rex field=message "\b(?<src_ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b \b(?<dest_ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b (?<src_port>\d*) (?<dest_port>\d*)"

props.conf extract

EXTRACT-fields = \b(?<src_ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b \b(?<dest_ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b (?<src_port>\d*) (?<dest_port>\d*)
If this reply helps you an upvote and "Accept as Solution" is appreciated.
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!

(re)Introducing the Splunk Community Champions + 2026 – 2027 Splunk MVPs ...

This program exists as a channel to empower and recognize Splunk advocates and help supercharge initiatives to ...

Introducing the 2026 - 2027 SplunkTrust cohort!

The goal of the SplunkTrust™ membership has historically been to acknowledge and recognize those who go above ...

Pro Tips for .conf26: How to Prep Like a Splunk Veteran

There’s no shortage of incredible content lined up for .conf26 in Denver, from deep-dive technical sessions ...