You may also want 'whereis' instead of 'which'.
I use cope to colorize my output, which makes 'which' useless to me for most common commands, but 'whereis' still works.
Edit for examples:
$ which ip
/usr/share/perl5/vendor_perl/auto/share/dist/Cope/ip
$ whereis ip
ip: /usr/bin/ip /usr/share/perl5/vendor_perl/auto/share/dist/Cope/ip /usr/share/man/man7/ip.7.gz /usr/share/man/man8/ip.8.gz