On linux, I use arp-scan:

Name        : arp-scan                     Relocations: (not relocatable)
Version     : 1.7                               Vendor: Fedora Project
Release     : 4.el6.1                       Build Date: Mon 10 May 2010 07:44:53 AM EDT
Install Date: Mon 16 Jun 2014 02:39:15 PM EDT      Build Host: x86-06.phx2.fedoraproject.org
Group       : Applications/Internet         Source RPM: arp-scan-1.7-4.el6.1.src.rpm
Size        : 529131                           License: GPLv2+
Signature   : RSA/8, Mon 10 May 2010 07:32:24 PM EDT, Key ID 3b49df2a0608b895
Packager    : Fedora Project
URL         : http://www.nta-monitor.com/tools/arp-scan/
Summary     : Scanning and fingerprinting tool
Description :
arp-scan is a command-line tool that uses the ARP protocol to discover and
fingerprint IP hosts on the local network.

This will do what you want.

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  << MCT >>   Michael C Tiernan xmpp:[log in to unmask] +1 (617) 324-9173
  MIT - Laboratory for Nuclear Science - http://www.lns.mit.edu
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