$ ls -al /usr/bin/w
lrwxrwxrwx 1 root root 19 Feb 11 2014 /usr/bin/w -> /etc/alternatives/w
$ ls -al /etc/alternatives/w
lrwxrwxrwx 1 root root 17 Feb 11 2014 /etc/alternatives/w -> /usr/bin/w.procps
$ w -V
w from procps-ng 3.3.10
$ who --version
who (GNU coreutils) 8.23
also "who --lookup" makes no attempt to look up the ip addresses either.