Help With RDNS For scr_ip in Syslog Message

[tbrichards]

I am trying to display the fqdn instead of the IP address for the internal host in a syslog message. In the example below, I would like to resolve the 10.10.10.100 address to FQDN and display that in Splunk, instead of the IP address.

Any assistance would be greatly appreciated.

Jul 31 01:46:08 [10.10.10.1] Jul 31 2012 01:46:08 EXT-FW : %ASA-4-338008: Dynamic Filter dropped blacklisted TCP traffic from inside:10.10.10.100/54749 (100.100.100.100/57315) to outside:69.63.190.74/80 (69.63.190.74/80), destination 69.63.190.74 resolved from dynamic list: 69.63.190.74/255.255.255.255, threat-level: very-high, category: Malware

[sdvorak_splunk]

Check out the example in this doc:
http://docs.splunk.com/Documentation/Splunk/4.2.5/Knowledge/Addfieldsfromexternaldatasources#Set_up_...