No guest DHCP through host WiFi in bridged mode

[JKu]

Hi there!

I'm experiencing problems with the combination host wifi, bridged mode and guest DHCP. I'm hoping not to create a duplicate.

• Host OS: Ubuntu 18.04
• Guest OS: Ubuntu 18.04
• Version 6.0.10 r132072 (Qt5.9.5)

The guest VM is sending DHCP Requests with its MAC address but gets no answer. When debugging on the hosts wlan0 I see 2 DHCP Requests - 1 from the MAC of the guest VM and 1 with the MAC of wlan0 on behalf of the guest VM - but still no answer. I'm using tcpdump to trace packets.

Debugging of the DHCP server shows incoming request and outgoing answers.

Other physical devices get IP addresses.

A friend of mine with Windows 10 for the host OS sees the same problem.

There are hints on the net to change the adapter type from 'Intel PRO 1000 MT Desktop' to '... Server' - unfortunately without success for me.

On cable ethernet it works fine. The same goes for WiFi using manual IP address configuration on the guest OS.

Cheers!

JK

[Socratis]

You know that the WiFi standard does NOT support bridging? When it actually works, it's because the hardware/software manufacturers have ignored the rules. Which is to say, it might or might not work depending on the combination or router/adapter/driver on the host. See: ​Bridging & Wifi - Supported hardware for some examples.

And here's a more technical explanation, pay special attention to the last paragraph: ticket #10019, comment:18.

Actually, I would read that whole ticket #10019, which despite your best intentions, this one seems to be a duplicate of.

[Socratis]

Forgot to add my personal experience, where Bridging-over-WiFi works fine in my home, but not in my office. Same laptop, same VM. Different router.

[Valery Ushakov]

Debugging of the DHCP server shows incoming request and outgoing answers.

Please, can you provide the capture from the DHCP server?