DHCP and Microsoft Hyper-V

stevenbecker2 · 2018-02-08T22:08:44.000Z

I was working on one of our servers today and notices that it had an IP address and subnet that is not within the range of our scope(192.168.120.1 - 192.168.121.255). Our network uses the subnet 255.255.254.0. As for the server I’m having a hard time trying to figure out why the IP is 192.168.9.10 with a subset of 255.255.255.252. Also I can’t directly remote in but I’m assuming that is because of the different subnets. Keep in mind I’m filling in for our Systems engineer while he is away so I might be overlooking something.

scottalanmiller · 2018-02-08T22:14:51.000Z

The range that you have is a different network than the server than you list, so unless you have some routing between them somewhere, they can’t talk because they aren’t connected to one another. Subnet masks don’t actually have to match (but they should), the issue here is that the networks don’t match. Those servers simply have no means of communicating.

So the first question is… are you sure that they should be able to communicate? If so, what is the source of the totally new network?

Dashrender · 2018-02-08T22:28:53.000Z

You could have VLANs or simply separate networks connected by routers, and that device is split off as such.

stevenbecker2 · 2018-02-08T22:34:48.000Z

I do have different VLANs but this server is not connected to the other network.

stevenbecker2 · 2018-02-08T22:44:02.000Z

Also all of my other servers that share the same virtual switch have IP within the correct range.

stevenbecker2 · 2018-02-09T00:05:20.000Z

Well I just did ipconfig /release and now it shows the right IP range but I don’t have a gateway address.

dextermahadeo · 2018-02-09T02:01:14.000Z

Personally, I think most admins don’t set servers to be DHCP clients unless a reservation is created in the scope so it’s possibly somehow that the server should be manual set for the basic parameters: address, mask, gateway, DNS.

It’s best you log into the DHCP Server and see what the scope is and probably set the Server to an address outside the scope. You can figure which by randomly selecting one outside the scope and PING it. Then run ARP -A from a command prompt. If you do not see it come up with a matching MAC in the resulting ARP cache list then it’s probably free to use until the administrator returns.

bethanyanderson · 2018-02-09T14:25:28.000Z

One question I would have is, is anything broken because of this? You questioned if you might be overlooking something, so is whatever is on that server not accessible by the clients who need it?