virtualbox.org

Hi all of you,

Primary platform/Host is Windows 7 OS SP1 64bit, 4 Core, 8GB Ram.


I’m using Virtual Box 5.0. My scenario is composed by three VMs:
-Windows Server 2012 DataCenter which acts as Domain Controller/DNS/DHCP and runs one SQL Server 2016 CTP3 (I know, it’s a bad idea install one SQL Server in the same DC). Ip: 192.168.1.3. Here, in my DCHP server I’ve configured Address Pool from 192.168.1.3 to 192.168.1.33.

-Windows Server 2012 DataCenter which has one one SQL Server 2012. Ip: 192.168.1.4

-Windows Server 2008 R2 which has a couple of SQL Server 2014 instances. Ip: 192.168.1.5

Everything thanks by using a Network Bridge (Virtual Box Host Only Network plus VMware Adapter)

My homework router NAT has 192.168.0.1. After been configured that bridge it brought me this IP: 192.168.1.0 and 192.168.1.1 ad DNS Ip and Gateway IP, hence these aforementioned IPs for my VMs.
I would like understand how it does really works. I mean, yesterday, suddenly in my host I saw how this bridge had 192.168.1.5 instead 192.168.1.0 Ip causing one issue with one of my VM…
After that, I configured fixed IP in my HOST Bridge. Is that correct? I mean, I don’t want changes in my virtualized network.

1)Is there a better way to configure one network like mine?
2)could I create another bridge in my HOST? This question is of paramount importance, because I would need to test multi subnet SQL Always On features.
3)Does my current configuration could affect to my DSL configuration?
4)Can you confirm the maximum number of IPs for this subnet? 255?

Thanks in advance for any input/hint/advice on my questions,

Your domain machines should run in a internal virtual network, not host only,and in their own IP subnet (192.168.1.0/24 as you have done is fine). You cannot bridge this to another network using a different IP subnet. You need another NAT router between the domain network and your home network. This router can be in a vm. Only the "public" side of the NAT router would be bridged to the physical network and have an IP in the 192.168.0.0/24 subnet.

eg

Internet
|
public IP
NAT router
192.168.0.1
|
physical machines (including vb host)
192.168.0.x dg 192.168.0.1
|
192.168.0.99 dg 192.168.0.1
virtual router
192.168.1.1 dg blank
|
domain vms
192.168.1.x dg 192.168.1.1

Thanks for your reply BillG.

You meant: unless I would configure a Virtual Router, if I wish another subnet would need I another physical router at home?

Question then now here is simple: how can I configure a Virtual router?

And another question:

Does my Network Bridge named "Mac Bridge Miniport" is, in fact, one Virtual Router??


Thanks indeed for your time

There are lots of router programs which will run in a vm. Google pfsense for an example.

A bridge is not a router. A bridge connects two networks which use the same IP subnet. If your physical NAT router uses DHCP and your DC also is a DHCP server, they cannot be in the same network. You need to separate them with a router, not a bridge.

Hi BillG, ok. When you say bridge for me would be a HUB or Switch

Yes, my DHCP server virtualized uses its own IP range, totally different than my NAT physical