OSX guests: all net cables disconnected between r112052 and r112114

[Socratis]

Most of my VMs have 4 network cards, 3 of them connected:

1. HostOnly, in the 192.168.20.0/24 range.
2. VBoxIntNet, in the 192.168.30.0/24 range.
3. Bridged, with my Airport card, usually cable=disconnected.
4. VBoxNATNet, in the 192.168.40.0/24 range, usually disconnected for Windows guests.

Starting with rev. 112114, all my network connections only on OSX guests are showing that the cable is not connected in the guest, i.e. there's no network whatsoever. Reverting to rev. 112052 magically connects the cables that were already connected in the configuration, i.e. 3/4. I tried rev. 112124 and that fails as well.

I changed the network adapters, since the OSX guests are the only ones using the "Intel PRO/1000 MT Server", but it made no difference.

All my other guests, (Windows, Ubuntu, Manjaro, Fedora, Mint, you name it) do not have that problem. Only the OSX guests.

From a 10.8 guest (for which I'll include the logs), excerpt of "ifconfig" for NIC1 (HostOnly), rev. 112052:

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	options=2b<RXCSUM,TXCSUM,VLAN_HWTAGGING,TSO4>
	ether 08:00:27:44:24:b5 
	inet6 fe80::a00:27ff:fe44:24b5%en0 prefixlen 64 scopeid 0x4 
	inet 192.168.20.101 netmask 0xffffff00 broadcast 192.168.20.255
	media: autoselect (1000baseT <full-duplex>)
	status: active

and excerpt of "ifconfig" for NIC1 (HostOnly), rev. 112114:

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	options=2b<RXCSUM,TXCSUM,VLAN_HWTAGGING,TSO4>
	ether 08:00:27:44:24:b5 
	media: autoselect (<unknown type>)
	status: inactive

I have tried all of my OSX VMs, from 10.5 to 10.12, with the same results.

[Socratis]

I don't know what you guys did, but with rev. 112223 everything returned back to normal. Thank you.

I believe this report can be closed as fixed. But a "here's what happened", wouldn't hurt either ;)

[Aleksey Ilyushin]

It is a bit early to close this one. In short 5.1.10 introduced a regression, skipping link status change interrupt delivery and OS X guests depend on it. We fixed it in r112176, but the fix caused some issues with Windows guests, so it was rolled back in r112230. The new fix is in works.

[Socratis]

OK, thanks aleksey for the update and the explanation. Anything I should be looking for in my Windows guests in particular? Or in any other guest for that matter?

[Frank Mehnert]

Fix is part of VBox 5.1.12.