[CentOS] Finding DHCP IP of guest system

[JohnS]

On Fri, 2010-07-16 at 20:59 -0500, Jay Leafey wrote:
> I had the same issue on my local network (DHCP server could not update 
> DNS) so I cobbled up a shell script that runs periodically to update DNS 
> manually.  It does a ping-sweep using "nmap -sP 192.168.1.0/24" and 
> parses the output.  The output (obfuscated and abbreviated) looks like this:
> 
> > Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2010-07-16 20:53 CDT
> > Host 192.168.1.1 appears to be up.
> > MAC Address: **:**:**:**:**:** (Unknown)
> > Host 192.168.1.2 appears to be up.
> > MAC Address: **:**:**:**:**:** (Compaq Computer)
> > Host workstation.local (192.168.1.5) appears to be up.
> > MAC Address: **:**:**:**:**:** (Hewlett Packard)
> > Host printer.local (192.168.1.9) appears to be up.
> 
> In my case, I added the MAC address/DNS name pairs in /etc/ethers and 
> use that to drive the process.  I've even got a few VMware hosts with 
> bridged interfaces, they work the same as the physical machines.
> 
> Admittedly, it's a heck of a kludge.
---
Awsome but a Day Late and a Dollar Short && Care to share that shell
script please.
&& Why you scrub the MACS?

John