bridged WiFi adapter - MAC address of guest not what I set?

Discussions about using Linux guests in VirtualBox.
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harisund
Posts: 33
Joined: 30. Oct 2008, 23:53
Primary OS: MS Windows 7
VBox Version: VirtualBox+Oracle ExtPack
Guest OSses: Windows XP, Ubuntu-10.04

bridged WiFi adapter - MAC address of guest not what I set?

Post by harisund »

Windows 8.1 host. VirtualBox 5.0.16.

Any Linux guest.

Single NIC. Bridged to my laptop's WiFi adapter. MAC randomly assigned as 080027A73E7F

In my router (running dnsmasq), MAC 080027A73E7F is set a static DHCP allocation to something.

When I boot my guest up, dnsmasq claims a machine with MAC 10233421.... requested an IP. DNSMASQ then assigns it an IP from its "unknown pool" and my Linux machine gets that IP, instead of the statically allocated IP.

What's going on here? Why isn't my Linux machine reporting the correct MAC to my DHCP server?
mpack
Site Moderator
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Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: VirtualBox+Oracle ExtPack
Guest OSses: Mostly XP

Re: bridged WiFi adapter - MAC address of guest not what I s

Post by mpack »

Well, I'm pretty sure that whatever the reason, it isn't because you have a Windows Host. Moving this topic to "Linux Guests".

Please post a VM log file. With the VM fully shut down, right click it in GUI. Select "Show Log" and save "VBox.log" (ONLY) to a zip file. Attach the zip here.

It would be good if you included a copy of the ".vbox" file in the zip.
Martin
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Primary OS: Fedora other
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Re: bridged WiFi adapter - MAC address of guest not what I s

Post by Martin »

The "problem" seems to be that real bridging / promiscous mode doesn't exist in the Wifi specifications.
Vbox works around this limitation in a way which shows the effect you are seeing: Only one MAC address can be active on a Wifi connection (in almost all cases) so you will just see the host Wifi MAC address on your router.
harisund
Posts: 33
Joined: 30. Oct 2008, 23:53
Primary OS: MS Windows 7
VBox Version: VirtualBox+Oracle ExtPack
Guest OSses: Windows XP, Ubuntu-10.04

Re: bridged WiFi adapter - MAC address of guest not what I s

Post by harisund »

mpack wrote:Well, I'm pretty sure that whatever the reason, it isn't because you have a Windows Host. Moving this topic to "Linux Guests".
haha, I am not surprised.
mpack wrote:Please post a VM log file. With the VM fully shut down, right click it in GUI. Select "Show Log" and save "VBox.log" (ONLY) to a zip file. Attach the zip here.
It would be good if you included a copy of the ".vbox" file in the zip.
Will do.
Martin wrote:The "problem" seems to be that real bridging / promiscous mode doesn't exist in the Wifi specifications.
Vbox works around this limitation in a way which shows the effect you are seeing: Only one MAC address can be active on a Wifi connection (in almost all cases) so you will just see the host Wifi MAC address on your router.
I recall reading about this limitation with Vbox's implementation of WiFi - bridges. However, it's not my host's WiFi MAC that's showing up on my DHCP server. It's something random.

In any case, I will double check.

(And no, I don't see this problem when connecting via a Wired bridge.)
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