IP conflicts...over and over again

[thehorse13]

You haven't given us all the info needed.

1) Are you using a single DHCP server with defined scopes? Is it setup correctly?
2) You can use any of the RFC1918 private address ranges. It makes no difference which you use. 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16
3) If you have a mixed scheme (DHCP and static) reserve the first 50 addresses within each class C for static hosts and then configure 51-254 in the DHCP pool in the scope for that subnet.

If you have this setup correctly, you will not see IP squatting issues. My guess is that you:
1) Haven't kept track of assigned IPs
2) Allow users to manually configure addresses
3) Don't have DHCP setup correctly
4) Routing may be busted up
5) Multiple DHCP servers are running

PS
Class C subnets have 254 addresses available for use. 255 is the broadcast IP.

Set up a computer with 2 NICs as proxy server as a gateway to the 'net

I can't imagine that this advice means what it literally says so let me clarify what I believe it to mean. Place a firewall between you and the internet and make this device your internet gateway. Placing a dual-homed host with IP forwarding on between you and the net would produce horrific results.

Enjoy.

--TH13