1

I have a Windows 2012 server running the latest Hyper-V. One of the clients is my network’s DHCP server . I just noticed that the host computer has 10 DHCP leases. Odder than that is the fact that I can’t ping any of those DHCP clients by IP address. If I try to ping my Host server by name, the only response I get is from the Static address that I assigned to it.

To explain.

My server name is W2012Host. The IP address is 192.168.5.5

The client is ClientDHCP1 The IP address is 192.168.5.2

The client shows IP addresses 192.168.5.100 -192.168.5.110. If I ping W2012Host, I get a response from 192.168.5.5. If I ping any of the IP addresses shown in DHCP, I get no response.

Any ideas?

2 Spice ups
2

Sorry …just need to clarify terminology.

when you say dhcp client, are you referring to workstation PC’s? or the dhcp server (as noted in the second sentence.

So in the dhcp server, you have the list of leases given? Or are you looking at the scope that has been created of 10 addresses, but perhaps none of them have actually been used?

Can you get on one of these “clients” and determine if its address matches the lease?

3

My bad. It’s really the DHCP server (I mentioned client because it’s the Client virtual server)

The 10 IP address are on the leases, not the scope. If I delete them, they reappear after a few hours. I can’t ping, or remote onto the real clients (any of the 10).

Thanks for answering.,

4

Reserved addresses for RRAS.

5

Thanks. Any way to get around that?

6

Are you using RRAS?

I’m having trouble deciphering your replies; is this causing any real problem?

7

The only real problem is that it’s taking a number of my DHCP addresses. As I add more users (and some users are using Wi-Fil) I’m getting concerned about my DHCP pool

8

You are currently using a private IP space (I am assuming a 24-bit mask), is there a technical reason why you will be unable to expand your scope of IPs once you deplete the remaining ~240?

9

No real reason, except m,y philosophy that if it ain’t broke, don’t fix it. If I don’t have to modify the subnet masks of all my peripherals, I’d rather not touch them.

Having said that, I’ve already made plans to go that route if I have to. And if I do, it will be well planned out and scheduled, before I’m desperate.

10

If 10 IP addresses is going to make or break you, I’d suggest flipping to a 23 bit mask (or less) now.

But if you’re determined, you can try a registry hack to reduce the number of IPs the RRAS server reserves (HKLM\SYSTEM\CurrentControlSet\Services\ RemoteAccess\Parameters\IP) Set DWord: InitialAddressPoolSize to something less than 10. I don’t know what the consequences for VPN clients would be if/when you do that. You may have to restart the server, or the RRAS service.

Another option would be to configure a separate subnet for VPN clients to use, and you can be assured they don’t clobber your in-office IPs.