utility that scans lan for client?

[Bruce Cran]

On Tue, Mar 24, 2009 at 12:43:34AM -0700, perryh at pluto.rain.com wrote:
> Mel Flynn <mel.flynn+fbsd.questions at mailing.thruhere.net> wrote:
> > On Monday 23 March 2009 19:59:36 John Almberg wrote:
> > > What I'm looking for is a utility that can scan a LAN for attached
> > > clients... i.e., computers that are attached to the LAN.
> > >
> > > I have one box (an appliance that I have no access to), that is on
> > > the LAN but I don't know what IP address it's using. I'd like to
> > > complete my network map, and that is the one empty box on my chart.
> >
> > security/nmap
> >
> > If the box pings, you can simply scan your LAN like:
> > $ nmap -sP 192.168.2.0/24
> 
> Or, with no ports needed:
> 
> $ ping -n -t 5 -i 10 192.168.200.255
> 
> Granted you need to know the broadcast address.  If you know the
> interface name, you can get the broadcast address from ifconfig:

That only works if the OS is configured to reply to broadcast ping,
which appears to be usually disabled nowadays. At least on FreeBSD 7.1
net.inet.icmp.bmcastecho defaults to 0.

-- 
Bruce Cran