two domains in one subnet -is it allowed?

[fenstrat]

We are migrating 3 windows 2000 domains into 2 windows 2000 domains. I want to completely get rid of one domain, and put the new on in it's place on the same subnet. I need to create the new domain and copy the domain objects to the new domain before demoting the original domain. I would like to do this all in one subnet without having to reorganize the network in the process. Is it possible to create both domains in the same subnet, and if so what kind of issues could arise? Would it be an easier job to create a new subnet specifically for this task.
Thanks

 

[Jpoandl]

There is no problem with creating two domains on one subnet. Win2K is "smart enough" to figure out who belongs to what domain.

Joseph L. Poandl
MCSE 2000

If your company is in need of experts to examine technical problems/solutions, please check out

http://www.NJCOMPUTERNETWORKS.com

(Sales@njcomputernetworks.com)

 

[N1ro]

Jpo,

can you create two identical pc names, each belonging to a different domain, under the same subnet? I tried this, and it when creating the second name it says the name already exists (even tho' it belongs to the other domain, completely seperate forest and seperate dns server)...the packet capture shows a nbt broadcast being sent out...I always thought that with a dns network the pc just asks the dns server if this name already exists. I'm creating a seperate subnet now for the development domain...but I was just curious if it's possible or not.


Thanks,
Mike

 

[MattWray]

No it is not. Even tho they are on different Domains, they are on the same physical Network. They would need to be on different subnets, due to NetBIOS broadcast....

Thanks,

Matt Wray
MCSE, MCSA, MCP, CCNA

http://www.sss-steel.com

http://www.total-tec.com

 

[fenstrat]

So, you are saying that it is possible to have 2 domains in the same subnet, but duplicate pc names cannot exist on the same subnet? One possible problem for me will be moving the computer accounts between the domains. After I move the accounts from the old domain to the new domain, will I have problems with the same machine objects existing in each domain? Or, does the move process delete the machine accounts on the source domain and create them on the destination domain. Do you think this will be o.k.

 

[jwi71]

It is possible.

Create your two seperate domains. Turn off Netbios. You should be using DHCP and DDNS. IF it is configured correctly, a PC can swap domains with no problem on the same subnet.

J

 

[AJP69]

In an ideal world you can get rid of Netbios, but we do not live in an ideal world. W2k still needs Netbios if you want to restrict login to a particular PC. If you have Netbios and your network is any decent size you need to have WINS (Yeeuk).

SO if you have Netbios you cannot use the same computer name.

How you proceed depends on whether you need an overnight switch or a migration. If it is migration, simply go around to each workstation and

Leave domain and join a workgroup (Build)
Change computername
Join new domain

If you need to switch overnight and you do not have time to get to each PC, create a second primary partition on each workstation and Ghost the existing workstation build to a second partition, then boot the second partition, change the name and join the new domain (or run sysprep). Then boot back into the first partition and change the boot.ini so it has a choice to load the second partition. Then when the time comes to switch over just change the default OS on the client.

Hope this helps

AJ

 

[fenstrat]

I don't see why I cannot move each client computer from one domain to another. When I move the computer it will only exist in one domain. There should not be any duplicate name errors because the machine will only be in one domain at a time.

 

[jwi71]

It will work as you suspect.

Your problem is, as stated above in several posts, Netbios. Netbios should not be running on your network if all your boxes are 2000 or XP. If you have non DDNS aware clients, your stuck. So pester your boss for funds to upgrade...won't be long before Win9x is EOL anyway.

You have two domain controllers on 192.168.1.0/24. Domain A and Domain B. On PDC of A, Config DDNS (if necessary) and DHCP, if so desired. Disable Netbios. Do the same for PDC of B. You will now have this: pdca.domaina.local and pdcb.domainb.local. On your box (comp.domaina.local), disable netbios. Switch from domaina to domainb. Switch back. Easy huh.

J

 

[fenstrat]

We are using all windows 2000. Thanks for your help. I am also setting up a test network for this.