[olug] DHCP rollout

[Eric Penne]

As some of you know, the company I work for is having IP address problems
(not enough), and they don't have a DHCP server to help with the change
from a /24 network to a /16 network.  The Cisco 675 router is also dealing
them fits but it is being replaced in the next week or two.

I'm proposing we set up a DHCP server with the current IP addresses
reserved so the DHCP server doesn't walk all over them when a new PC gets
connected.  I wrote a script that pings all the addresses on our /24 then
grabs the MAC address from /proc/net/arp.  I'm hoping that by doing this I
can create a DHCP config with these MACs and IPs being protected (roughly
DHCP'd static IPs).  I've already done the leg work and anybody that wants
the script is more than welcome to it.

Is there a better way to do it?  I've looked at arpwatch but it didn't
seem to work very well for me.  I thought it was because I'm on a switched
network.  My scripting approach seems to be more proactive about getting
the MACs than arpwatch since I actively ping the machines.

Most machines are off today since the plant is in a "slow down" period. 
I'll have to run this script regularly during the different shifts and
over a few days to try to catch vacationing office workers and transient
PCs out in the plant.

Later
Eric Penne