dnsmasq/contrib/reverse-dns

The script reads stdin and replaces all IP addresses with names before

outputting it again. IPs from private networks are reverse looked  up

via dns. Other IP addresses are searched for in the dnsmasq query log.

This gives names (CNAMEs if I understand DNS correctly) that are closer

to the name the client originally asked for then the names obtained by

reverse lookup. Just run



netstat -n -4 | ./reverse_replace.sh 



to see what it does. It needs 



log-queries

log-facility=/var/log/dnsmasq.log



in the dnsmasq configuration.



The script runs on debian (with dash installed) and on busybox.