topic How to extract source and destination IP fields? in Splunk Search

How to extract source and destination IP fields?

rootchin — Wed, 01 Mar 2017 16:23:00 GMT

I am trying to configure various search fields for a firewall log from the field extractor but Splunk is pulling up some incorrect results. Any help would be appreciated. The two images are examples of the logs.

Here is the expression that incorrectly pulls up some results.

^[^/\n]*/(?P[^\(]+)

Re: How to extract source and destination IP fields?

richgalloway — Wed, 01 Mar 2017 16:54:09 GMT

What results are you getting and what do you expect?

A copy-and-paste of the event text is more helpful than a screen shot.

Re: How to extract source and destination IP fields?

hgrow — Wed, 01 Mar 2017 17:25:01 GMT

As richgalloway mentioned copy past would be usefull. By the title I assume you are looking for the source and destination fields.

For your first example inside:(?<src_ip>[^\/]+)\/(?<src_port>\d+) dst outside:(?<dest_ip>[^\/]+)\/(?<dest_port>\d+) might be a fitting regex.

something something ... deny tcp src inside:123.123.123.123/444 dst outside:111.222.333.444/555 ....

I personally would go with another extraction for your other example since both events are not quite similar but I'm sure someone else would combine both.

For the second example permitted \w+ \w+\/(?<src_ip>[^\(]+)\(\w+\) -> outside\/(?<dest_ip>[^\(]+) might fit.

something something ... permitted udp dmz/111.222.333.444(123) -> outside/123.123.123.123(123) ....

Re: How to extract source and destination IP fields?

bshuler_splunk — Wed, 01 Mar 2017 20:31:24 GMT

First Extraction: https://regex101.com/r/CFOb1y/1
Second Extraction: https://regex101.com/r/43d4OA/1

Obviously, if you provide a full log, I could help more, but this should get you started.

Also, check this out: https://docs.splunk.com/Documentation/Splunk/6.5.2/SearchReference/Scrub

And if you want a CIM compliant TA for Cisco ASA, I would try: https://splunkbase.splunk.com/app/1620/

Odds are, the Splunk extractions are better.