Mass Reverse-DNS Lookup

I needed to quickly browse through some web-server logs and pull out the hostnames which were accessing the web-server (to see where people were originating from).

The following single linux command will pull the IP address out of the apache log (for a particular date) and do the reverse DNS lookup for me:

cat access.log | grep ‘1/Sep’ | awk ‘{print $1}’ | sort | uniq | xargs -n1 host | grep -v ‘not found’

just in case i ever need it again….

1 comment

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>