PPPoE fails over bridged HP8510w 4965AG WLAN card

[Kinnoken]

I have a problem where I have a host machine, an HP8510w laptop with an intel 4965AG WLAN card. I am running Vista 64 Ultimate (same problem with Win 7 64 RTM) with a guest machine running Windows XP Sp3. The most important aspects of this setup is that the guest machine is set to be bridged to my WLAN card (Intel 4965AG). I am using static IP's with a router.

After the Guest OS is installed, I have configured an IP address. I can ping the router from the Host OS and I can also ping the router from the Guest OS. All other aspects of networking seem to be working. (I do not use DHCP purely because of my network setup but I feel this is unimportant).

I have several PPPoE accounts and a router that is in bridge mode. When I try to initiate a PPPoE connection in the Guest OS (WinXP), PADI packets leave the guest machine, go through the bridged network, reach the router. The router then sends a PADO response which can be seen on the Host OS and is also passed on to the Guest OS.

Unfortunately, the Guest OS is ignoring these packets as the target MAC address does not seem to be for the Guest OS (Which is understandable, but surely the bridging driver/service installed on the Host OS NIC is supposed to correct this?)

This seems to be a problem with the bridging driver/service for VirtualBox. This may not be of any concern to you, but the problem also exists in VMware Workstation. This is not a problem for Microsoft Virtual Machine though.

I have discovered a slight workaround. If I set the MAC address of the virtual network card in the guest to the same MAC address of the Host OS WLAN card, the PADO packets are relayed and it now works. Unfortunately, this causes other problems with Linux Guest's trying to use the same workaround and I cannot use this solution permanently.

I have attached the Vbox.log, as well as two wireshark captures from both the host and the guest machine.

[Kinnoken]

VirtualBox log as requested

[Kinnoken]

Wireshark packet capture from host machine

[Kinnoken]

Guest OS packet capture

[marzen]

I have the same issue here and still in v5.2 there seems to be no fix for this. I also guess that the problem in #14404 has the same root cause and was closed with wrong assumptions.

I am using an AVM Fritz!Box 7390 as PPPoE modem with passthrough enabled and a VirtualBox host with an Intel Centrino Wireless-N 2230 Wifi adaptor that guests use as Network Bridge.

All PADI requests to the network are sent out with the Source MAC of the host but not with the source MAC of the guest as I could see in a pcap trace. Of course the PADO responses never find their way back to the guest like this. If I use a wired connection with a Network Bridge via an Intel 82579LM Gigabit Adapter it sents out the PADI requests properly adressed with guests source MAC. Thus the PADO responses are going backwards the right way and are received by the guest correctly.

This is a general problem imho with WiFi-Adaptors used as network bridge which not has been solved yet.

BR marzen

[Socratis]

See ticket #10019, comments 18 and 19.

[Valery Ushakov]

Right, PPPoE is not supported. "Bridging" to wifi is not actually bridging, but more like an Ethernet-level NAT. For IP traffic we can look at the destination IP address and dispatch incoming packets accordingly. With PPPoE there's no such indication. Some heuristic can be worked out, probably, but this is not a common usage scenario, so it's rather unlikely that this will ever get any attention/resources.