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I'm going to upgrade some servers from 2008 to 2016 clean install, the servers are domain controllers and file server, is it possible to use the same name and ip when I turn off the old server, what's recommended in this case since many services will be pointing to the old name and IP?

Fodi
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  • Domain controllers are tricky because, ideally, you want to promote the new server (therefore new IP address and new name), transfer all the roles over and then demote the old server. What kind of "services" is relying on the old name? I'm wondering if you can't just get away with adding another DNS entry that uses the old name to point to the new server IP address. – Carlos Feb 10 '20 at 18:47
  • Thinking further, it sounds like you have multiple domain controllers so you can conceivably de-promote one of them, decommission it, replace the server with the new hardware and promote it using the same IP and name. That would work and you can proceed with the other domain controllers in the same manner. Just backup, backup, backup.... :) – Carlos Feb 10 '20 at 18:49

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Domain Controllers: It is possible, but not recommended. The clean build would need to be built from a backup / restore of the AD environment, and you would need to do all of your AD services / servers at the same time without the old servers online. I won't describe the details here, Technet does that much more thoroughly than I could in a quick note. A critical consideration is that the AD environment and service configuration includes SIDs, names and IP's across a whole host of settings, and the relationship between all of those is critical for AD services to continue to replicate and work correctly.

A more common practice (and easier, frankly) is to build a new clean machine (new name, new IP), add the AD service(s), promote the server (which adds the server to the AD environment and updates the AD database in a coordinated way) and then demote and remove the old server. See Technet for the instructions on promotion/demotion.

If you have services that are hard configured to Name/IPs, I would recommend you update those to use DNS, DHCP or similar dynamic source records. Once you do that, you make your life easier in so many ways.

File Servers: Are you using any DFS services? If not, it is possible, and relatively straight forward. Build the new server with a temporary name and IP, add services, replicate your data on the new server, rename the old server to a temporary name and IP, rename the new server to the original name and update IP to the original IP.

If you are using DFS, I would recommend you use the DFS service configuration to add a new file server (new name and IP) to the DFS-N scheme, then use DFS-R to replicate the shared files. Once you have replicated all data, then you can remove the old server from the DFS-N scheme and DFS-R replica. Once removed you can delete the server.

Since you are asking these question, I recommend you look into use of DFS for file shares, and eliminate dependencies on fixed names/IPs.

Yaro
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  • Thanks Yaro, I started this with one of the DC I transferred roles and services but unable to demot the old server also I can't get the server replicated no sysvol or netlogin folder appear in the share. Maybe because I shutdown the old server and use the same name and ip?? – Fodi Feb 15 '20 at 13:09
  • You must have all servers up and running for the entire process. I recommended a sequence of renaming so you can get to a point of new server with the old DC name. That process of renaming ensures the computer objects and settings are updated throughout the domain. If you shut down the old DC before demoting, renaming and changing the IP, you -will- have conflicts in the database as the old server computer objects still exist, but with a different SID and the same name. – Yaro Feb 15 '20 at 16:14
  • I didn't use the name, the used the old ip only – Fodi Feb 15 '20 at 17:03
  • Change the IP to a temp address on the new server and get everything healthy with the old server up and running. Just make sure you do not have DHCP running in both. Once you get a clean DC health report, then demote the old server. Again, once you get a clean AD health report, then change the IP on the old server. Repeat health check and IP change on new server. – Yaro Feb 15 '20 at 17:08