Opened 4 years ago
Last modified 4 years ago
#20099 new defect
bridged mode not working in VB on macOS Big Sur for VB windows clients
| Reported by: | pbvbox | Owned by: | |
|---|---|---|---|
| Component: | network | Version: | VirtualBox 6.1.16 |
| Keywords: | bridged mode | Cc: | |
| Guest type: | Windows | Host type: | Mac OS X |
Description
As posted in the VB Forum: Finally got to the bottom of the issue after finding a few hints, pointers and bits of information at various places.
After the upgrade from Catalina to Big Sur, networking caused several issues in VB windows instances. I've always used bridged mode with no issues for both wired and wireless connections before the upgrade.
My symptoms , In bridge mode DHCP in windows failed to obtain a valid IP address, starting with duplicate found and quickly followed with a 192.168.1 address that would not give a proper connection , I use 192.168.0 subdomain. Could not get neither the wired nor the wireless connection to work.
When setting NAT mode the VB windows instance, VB would fatally crash the VB windows instance, so not windows but VB crashed.
I concluded that the last issue must have been caused by VB drivers being messed up after the Catalina to Big Sur transition.
I downloaded the 6.1.16 VB version and used the uninstall script ( available in the finder window when opening the vb.dmg file) to remove VB from the mac. Don't worry it only removes the drivers and VB itself, not any of your configs or VB disks and client images. Then re-installed VB. This got NAT back working.
Bridged mode still had same issues for windows clients, it has something to do with change in behaviour of how big sure handles MAC addresses by the looks of it. The fix is that you have to give the network adapter in VB that is mapped on your mac network adapter the same MAC address as the MAC address for the adapter on your MAC. This is not a good permanent fix as you this prevents you to have more than one VB client run on your MAC as all you would get duplicated MAC addresses on your system. Be aware of that. Also if you use DHCP with preset IP addresses, each VB windows client will get the same IP address.
I also note that this problem (packets not getting through bridged interface) is also occurring on Linux hosts. The same awful work-around (change guest's MAC) fixes the problem, but is unusable for systems with more than one guest sharing the same interface.