Anonymize IP-addresses in log-files

 Anonip masks the last bits of IPv4 and IPv6 addresses. That way most of the
 relevant information is preserved, while the IP-address does not match a
 particular individuum anymore.
 .
 It can be either used to anonymise existing log files, or directly by a service
 if it supports loging to shell pipes. Configuring the Apache httpd or nginx is
 very easy, so that unmasked IP addresses are never written to any file.
 .
 With the help of cat, it's also possible to rewrite existing log files.