1

I have a vlan I am using as somewhat of a limited sandbox. I want to start moving my servers over to it. I want to start with my 3 DCs. My DNS is an active directory integrated zone as are the other divisions. I am thinking that all should go well if I manually update DNS with the new ips and do a repadmin /syncall. What else should I be considering? Will I have to manually update Sites and Services as well? thanks

2 Spice ups
2

Yes, you’ll need to update sites and services with the IP ranges or you’ll get errors in the event logs stating that it isn’t sure which site needs to authenticate users.

It’s not a major issue but it is annoying :slight_smile:

3

So under subnets just *add the new range? In other words, once I separate the DCs from the rest of the lan, do I keep both sets of ranges ? ex:

Division A

172.16.0.0 (current flat network)

192.168.0.0 (vlan network that will include the DCs)

Keep both in the ‘subnets’ section of Sites and Services or delete 172.16.0.0 and replace with 192.168.0.0 for Division A?

Thanks

4

Yes, that’s all you need to do.

I’d also suggest that you move one DC and test the process out. Once you change the IP address reboot the box so that it updates everything with the new IP.

5

Are your DCs also your DHCP servers? If so you’ll want to add a helper address on the old subnet pointing to the new address of the DC/DHCP server(s).

1 Spice up
6

Yes, one is thanks for the catch!

7

Ok Ethan, from a Poblano to a Tabasco, as long as the DHCP range is listed; won’t everything be ok since the DHCP server will advertise itself as such? I only ask because I am unsure where to config the helper address.

8

if its a new subnet being routed by a layer 3 switch or router you will need a dhcp helper. without a dhcp helper enter subnet a will not know that it has to go to the dhcp server in subnet b to get IPs for the machines in subnet a.

9

Ok, it sounds like I’d be configuring that on my Fortigate since my core switches cannot inter vlan route. I think I have enough now thank you all.

10

Actually no. Clients send out DHCP requests to the local subnet asking for a DHCP server to respond but these requests don’t automatically cross to other VLANs. You need to add a helper address to each subnet without a DHCP server on whatever device will be doing the VLAN routing (i.e. layer 3 switch or router).

Yup, sounds like you’ve got the picture.

11

Can i ask why you want to do this?