Multiple bridged virtual adaptors does not work

[takai]

Im currently having an issue with a fresh installation of VirtualBox on a fresh install of XP, running a fresh install of Ubuntu as the client OS. Basically i want to be able to use the Ubuntu client machine as a gateway between two networks, one running on a Class A and the other on a Class C. I was hoping to be able to use the same ethernet adaptor to bridge the connections out, as theoretically due to the OSPF routing this shouldnt affect a thing (and indeed we do this on Linux using virutal interfaces bound to the same network card).

As such this is how i have setup the NICs:


However, when i run the system only one of the two ethernet devices comes online. The other doesnt complain at all but obviously cannot transmit or recieve anything over the virtual adaptor. Is this a limitation of the system, or a bug, or have i misconfigured something?

[Perryg]

takai,

I am going to have to say it must be a configuration error.
I have Windows server 2003 with dual virtual nic adapters one in the class C and the other in class A performing DHCP to class A for remote VPN and it does in fact operate as it should. You need to do your own routing and I provide the DNS for all host and guests.

[Sasquatch]

I suspect the config problem too. The main reason is that you used the same adapter for both virtual interfaces. That won't work properly, you have to bridge separate ones.

[Perryg]

While I may be doing it wrong (wrong way me) and I am sure there are other ways to make this happen. I do have it working and using the same adapter.
I just do it by routing in the guest since my cheap router can not handle the multiple address. I can do this when I fire up my cisco router but it makes too much noise and uses too much electricity. Trying to be green you know. See screen shot below.

[Sasquatch]

I stand corrected. Thought that might be a problem, guess it isn't.

[Perryg]

Actually it is and it isn't. As long as the adapter has a different MAC which is what the traffic is really sent to anyway it should work fine. You have to be really careful what you do and how or you can create a router storm, and those are not pretty. Anyway as I said it probably is not supposed to work this way anyhow. But hey it works for me

[takai]

Yeah, thats exactly how i have it configured. Will post up the settings in a minute if people want. But i cant figure out why its not bridging the second adaptor properly.