expand the DHCP scope range best practice

bickybudha1182 · 2014-10-04T09:03:27.000Z

Hi I have a Server 2012 DHCP server; And one of the scope used by windows workstations & printers is running out of ip addresses. These devices are on VLAN 20 whose ip address is 10.100.32.1. This scope has some ip addresses been reserved and the devices on this scope are configured to get ip address automatically.

Currently it is on 10.100.32.0/24 (10.100.32.2 - 254) and I would like to change the subnet mask to /23, so what is the best way of doing it ?

Do I need to first delete the scope and re-add it ?
And what about the reservations, can I backup and restore ?
Once scope is added, beside modifying the VLAN ip address on the switch, is there anything else I need to do ?
Do I need to restart all the workstations/printers after scope changes ?

Any help would be much appreciated, thank you.

pbp · 2014-10-04T16:46:56.000Z

Expanding the subnet alone is a quick patch or panic fix. Seems odd there is a subnet and VLAN.

A better understanding of the network setup would help—

How many users are the?
How many hosts are there?
What has the growth rate been?
How are WAPs/wifi, VoIP, servers, and arranged?
etc

joshuacrutchfield · 2014-10-04T19:10:23.000Z

No you shouldn’t have to delete the scope
Since you didn’t delete the scope the reservations should still be there. However as best practice I always move my printers past the .220 range and only allow the dhcp server to issue from 10 - 220. And set up the reservations for the .221.
Not that I know of besides changing the mask on the router
No you shouldn’t need to restart. The computers and workstations will renew when their lease expires.

Here is a link to Microsoft that can help out as well.

learn.microsoft.com

Increase the number of IP addresses on a subnet - Windows Server

Describes three methods you can use to change the number of IP hosts on any given subnet.

bickybudha1182 · 2014-10-06T05:53:59.000Z

@RougePacket
Entire network has 1400+ users, Currently this scope has nearly used the 85% of the ip addresses, there are about 220 devices/hosts on this network. We are looking to add more devices on this network (10.100.32.0). WAP, VoIP, Servers are on completely different network.

My predecessor has separated the network as:
vlan 10 - 10.10.10.0 - Servers
vlan 20 - 10.100.32.0 - Staff Windows PCs, Printers.
vlan 25 - 10.200.32.0 - Student PCs, Printers
vlan 30 - 10.101.32.0 - IP Phones
vlan 40 - 10.102.32.0 - WAP
vlan 50 - 10.103.32.0 - CCTV

thank you.