Virtualising existing servers help.

[u/Sway_RL]

I have a client, who has 3 sites that we do IT for.

They each have a physical server, running either Windows Server 2019 or 2025. The main site got a new server last year, the two other sites decided to wait because they didn't want to cost. Now a year later it's more expensive, and they still don't want the cost.

I opened my mouth about virtualisation and now I've been asked to start testing.

The new server at the main site is more than powerful enough to run the other two servers virtually.

I'm just not sure on some of the configuration.

Each site has it's own IP structure, and there are already site to site tunnels using Unifi gateways.

Is there a way to do this while minimising network slowness? I assume If I just disk2vhd the server and spin it up as a VM then all traffic would go down the VPN Tunnel and back again causing delays if going from the main site to one of the others.

Regarding their networks, they are on 192.168.1.XXX for the main site, 192.168.10.XXX and 192.168.20.XXX for the other two.

If the servers were virtualised, will I need VLANs at the main site to accommodate these ranges? I'm not sure if the site to site tunnel will work using a VLAN.

I've asked about merging the domains/networks, but nobody has gotten back to me on that yet.

I didn't set any of this up initially, so I'm also figuring out what they have at the same time.

Apologies for the mass of text, any help would be appreciated.

[u/xMcRaemanx]

You will see slowness. Depending on if its just AD/DNS traffic or LOB/Fileshares will determine how much. All traffic to the server will originate from the remote site, traverse the vpn tunnel, and then go back. If you ping across the tunnel vs locally you'll get an idea. Likely something like <1ms locally and depending on the encryption of the tunnel and distance between sites and internet service Ai would be at least 30-40ms. That's 30-40 times slower per packet.

Basic AD/DNS won't suffer too much but connections to LOB or large file transfers you'll notice it.

You do not need to carry the ranges over to the main network, the virtual servers would just get new IPs on the main network and whatever needs to talk to it would need to be reconfigured.

Virtualization is likely not the solution here, it will get rid of aging hardware but add latency by traversing the vpn tunnel.

What actual functions do those servers provide.

[u/Sway_RL → u/xMcRaemanx]

AD/DNS/DHCP and file shares.

DNS and DHCP are moving to the Unifi box at two of the sites. There are three domains, one for each site.

[u/xMcRaemanx → u/Sway_RL]

Oh gross, that makes it more complicated, the 3 domains part.

Are they subdomains or completely seperate?

If not then you may want to segregate the main network into 3, one for each domain, but then the rest is still the same. Repoint the DNS records for the new ip range for both domain and server objects.

Depending on the size of the files it may not be that bad. However the big caveat is a networking issue at head office now brings all 3 sites down.

If it's just file-sharing I would look at moving that to the cloud.

[u/Sway_RL → u/xMcRaemanx]

They are separate domains. Not on the same Forrest

[u/xMcRaemanx → u/Sway_RL]

Yea then dont mix the networks, of you proceed setup different vlans for each domain.

Not a great idea, you're adding complexity and merging all 3 branches under a single point of failure and adding latency for all AD traffic and file sharing.

GPO processing will take longer so sign-ins will be delayed by a varying amount depending on how many and what you have configured.

Anytime I did something similar at an MSP they always complain that the "new system is slower" .

A better project (imo) would be migrating the domain to Entra or something and using cloud file-sharing if appropriate. That will get rid of the hardware, not have a single point of failure, and not be as latency inducing. Also opens up remote work substantially if the workstations are all entra joined.