Blocking machines from getting DHCP

[PoliMalaka]

Is there a way to limit the addresses given out by the DHCP server to certain (know) machines? Of course we could do leases, but we have too many devices to even begin to start with that.

Or Can we block a particular machine (MAC addy) from getting an address?

 

[Phobos1821]

yes, you can make a 'reservation' on the MAC address, and assign it an invalid IP address. Example

Reservation Name: blocked_mac
ip address: 192.168.3.3
MAC address: 00:42:33:22:11

 

[PoliMalaka]

In order to do that i had to exclude a portion of our existing IP addresses from the DCHP scope.
1. Make an exclusion range (20 addresses)
2. Then create the reservation with a valid IP but with bunk network info such as gatewate, WINS, DNS, etc.
I'll need to test this out first, but it isn't the bet option in that it seems contrived.
Thanks for the tip and I'll let you know if it works for us.

 

[Phobos1821]

You can create a new scope for a subnet currently does not reside within your network.
AKA 172.16.x.x
Then make your reservations within the scope their. Then when they DHCP, they get an IP address outsite your subnet, and cannot communicate with your network.