virtualbox.org

Having a multi-vm-machine setup I need to put two or more VMs into a bridge.

It used to work on 2.0: two tap interfaces in a bridge
This does not work in 2.1.2: arp request are visible in the linux guests and on the bridge, but do not receive a response from the other guest
(The same guest that did work before...)

I tried attaching the if immediately to a bridge: this fails due to a generic name 'Failed to open/create the internal network 'HostInterfaceNetworking-br20', which is taken for all VMs that are expected to sit in br20 ...

What is the way to go?

[edit: PS: I want to be able to sniff all the traffic on the network, and best want to change the bridge a guest is connected to on the fly, e.g., mobility emulations ...]
Best,
fme

I may have a similar problem. Version 2.1.2 broke my tap interfaces. Guests
can no longer ping each other. Version 2.1.0 works ok.

If you use the TAP interfaces and bridge so that all the VMs can communicate with each other, and the Host does not need this connection, you can use Internal Networking. It's designed for this.

Sasquatch, probably you did not read 2 post above. They want to have BRIDGE i.e. - access all the local network, every machine. It seems to be a tradition on this forum to tell people what they must do instead of answer how to do what they want to do.

I also need this feature soon, btw. Is there a solution?

I thought you were talking about VM to VM communication only. Must have misread it, or misunderstood.

To get the 'old' connectivity, you just select your physical connection you would otherwise bridge with. You can still create TAP interfaces, but not with VB itself. You need the uml-utilities package for that.

" You can still create TAP interfaces, but not with VB itself. "
Sure I can and I did. But it just does not work. There must be some blocking bug in the code. Downgrading to 2.0.x makes it work again (Of course, there are configuration changes necessary, which I also did).

You can't create interfaces from the GUI anymore. The command, VBoxAddIF is also removed. If you can, then you are using some modified version or not 2.1.x.

Sure. It's the do-it-manually way. tunctl -u xxx -t tap22; brctl addif br20 tap22; ifconfig tap22 0.0.0.0 up; sysctl -w net.....forwarding=1; etc.
And then in the gui or VBoxManage ... -hostif tap22.
Then, as said above:
- guest A (tap32 in br20) pings B
- arp req for B visible in br20
- arp req for B visible in eth0 (guest B)
No arp response visible anywhere.

For B to A it's the very same behaviour. At the very same time.

You said to create the interfaces from the GUI, which is not what you are doing. You create them using a different program on the CLI, then select the created interfaces from the GUI. This is what I've been saying you need to do.