Server Upgrades, VLans, DNS, DHCP

[newpersn]

During the summer we are looking at upgrading our DC's to 2012R2.

 

We had outside help from another company when we moved to 2008r2 who help us with VLANs and VMWare (@mrbios will tell you how great the help was....)

 

Our current setup has a DC on each vlan. (also does DNS/DHCP) (so 8 Vlans with a server on each)

 

What would be the best setup on setting up the upgrade?

 

Can i create a new PDC server on 2012r2 with 2/3 servers with mutilate NICs doing each vlan? (when promote the new and de-promote the old ones (first time me doing this so please bear with me))

 

PS we will be looking at moving to Hyper-V instead of VMware we only have 4.1 unless it a free upgrade to latest version. (we have paid for vmware i believe and not running the free version)

 

Hope you can understand this....

[mukz]

Is newpersn, is there any reason you have a DC on each separate vlan? I dont know about others but i would prefer to have servers on a specific vlan. Do these other vlans have any other uses?

 

Moving from vmware to hyper v is pretty easy. If you can set up a failover cluster i would highly recommend and balance servers across the cluster.

 

In terms of the DC upgrade, crank a new VM on any vlan of your choice as i dont know how the set up is. The approach is to always introduce new DC's and phase out old ones. You will want to introduce a 2012 DC, transfer the FSMO roles over to it, phase out the old 2008r2 DC's, then proceed to update the forest and domain levels. Obviously making sure you are ready for the 2012 level.

[mrbios]

First off, demote 6 of those DCs, promote two new 2012R2 ones, move the FSMO roles across to the 2012R2 ones, demote the 2008R2 ones. Setup ip helpers for DHCP for all the other vlans and setup DHCP failover between the two new 2012R2 DCs. Happy days.

 

I did the same thing last summer, there's not a trace of outside "help" configuration left anymore

 

jatech have a hand in that setup per chance

 

EDIT: Actually do it in this order:

Create two new 2012R2 VMs, promote them as DCs, let replication have enough time to sort itself out and make sure DNS, DHCP etc are setup correctly on them. Put these on your infrastructure/central server vlan rather than any building specific vlan.

Then setup DHCP to be done from one 2012R2 server, i think you need to setup ip helpers on your router for each vlan and just configure all the scopes on that one server. You won't need multiple nics/vlans assigned to that server this way.

Then once DHCP is working (obviously make sure to disable each DHCP scope on the other DC prior to enabling the scope on the 2012R2 server) move the FSMO roles to the 2012R2 ones.

Double check DNS and DHCP are correct

Demote all the 2008R2 ones.

Setup DHCP failover between the two remaining DCs.

 

I might have missed something, so anyone feel free to add/adjust what i've said. I have to remind myself of the process every time i do it as it's one of those "every 5 years" type jobs haha

Edited March 12, 2016 by mrbios

[LytchettNM]

All I can say is OMG a DC per VLAN crazy people setting that up for you.

I set ours up last summer 3 server rooms 5 host servers across 2 clusters. It was a massive amount of work but we also choose to create a new domain as we moved from 2003 fictional level on 2008 servers to 2012r2.

Still a little nervous about but everything into a failover cluster so we also added a server to host our primary domain controller within a VM which allows for us to backup the PDC, we then added 2 other dc's one within each cluster and it works very well.

Our new core switching also does inter VLAN routing /ip helpers so we have VLAN's per building and cross site VLAN's for printing and wi-if etc.

I would recommended failover DHCP across 2 server too with multiple scopes that way you can control all IP's from MMC.

[newpersn]

so... so basic English....

 

Set up 2 x DC2012 R2 and make them a DC. Setup DHCP and DNS roles and make sure there are fine. (Make sure they are on our VLAN2 (Infrastructure vlan)

 

On one of the new servers set up DHCP with all scopes (turn off old scopes on the 2008r2 then the new ones are set up) Sort out IP Helpers on switch. (this is where im going to get confused)

 

Move FSMO roles over to the new 2012R2 (both)

 

Check DNS and DHCP are running correct.

 

Start killing the old 2008r2 servers (demote and remove all services?)

 

Setup DHCP failover between the 2 new 2012r2 servers? (might have to do abit of research on this)

 

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I think i will use an phyical server and a vm on a another server? or am i better off using 2 VM on different hosts?

[LytchettNM]

Hi newpersn sorry for not replying sooner been a little busy.

 

Yes setup the 2 x DC's and get DNS & DHCP Working, the failover DHCP thing is easy to setup just have to remember if you need reservations you have to replicate between the servers for every change so setup one DHCP server first get all your bits setup correct then add the second DHCP, if I remember correctly if was a simple wizard.

The key to getting all this working is getting the routing correct and ip helper / forwards setup on the device that is going to control your network, spend some time understanding this piece.

Can you setup the new servers and a routing device without affecting your production network as you can get it right before moving everything over?

When you have decided on the infrastructure setup of your server network you should then be able to take a look at the best place to put your FSMO roles, I opted to host my PDC with all FSMO on a VM which is hosted by hyper-v on a server which is not part of a cluster with two other SDC's one on each of our clusters to spread the load and support HA.

I'll try to check back here and help when time allows if you need more help.

Darren

Edited March 17, 2016 by Techforyou