Bridged Networking Not Working

[PhilMa]

Hi, I am running into an issue that DID work in the past, but I am unsure what changed other than the fact that I updated from .14 to .16.

I am working with a client, configuring SCCM. Because I'm doing things like PXE booting and other imaging stuff, I need bridged networking to work so that my VM has an IP address on the same subnet as the host adapter. (Essentially what I'm saying is that NAT is not ideal because I need the VM to work, networking-wise, like a standard device on their network).

Here is a little bit of setup information:
- The Host machine is running Windows 10 Pro, x64 with VirtualBox 6.1.16. It's important to note that the host machine is running on a VMWare infrastructure. It says that it's running on '5.5 or later', and the VM Tools version is 9355. It's attached to a virtual network adapter that seems to have very little settings worth noting.
- The host machine has two adapters - Ethernet (Intel 82574L Gigabit Ethernet) and VirtualBox Host-Only Network. The Ethernet one is the NIC that is provided by VMWare. It is set to DHCP and is getting an IP address (10.3.20.2) properly. The Default Gateway, 10.3.1.1, is pingable. I have no problems with connectivity on it.

- The guest machine is Running Windows 10 Pro, x64. It has a bridged adapter, type intel PRO/1000MT Desktop. The adapter chosen to be bridged is the intel 82574 from above. The DHCP server is able to provide an IP address to it! Also, i am able to ping the host machine, and the host machine is able to ping it. Beyond that, the guest machine cannot seem to connect to anything else. It cannot ping the default gateway. It cannot ping anything else on the subnet - only the host machine.

Can anyone provide me any details on what to try? It seems like the host is not properly passing traffic beyond itself to the rest of the network.

[scottgus1]

Sounds like you have nested virtualization running:
PC > VMware > Win10 > Virtualbox > Win10

You had the 2nd Win10 accessing the PC's LAN, then you updated the first Win10's Virtualbox to 6.1.16, and lost the LAN.

As a test, though this is not the ultimate goal, please try the 2nd Win10 set to NAT, and see if you can ping Google at 8.8.8.8 (check that you can ping 8.8.8.8 on the host PC and in the first Win10, too, to check the full network chain).

If NAT allows Google to be pinged, but Bridged does not, then it would sound like the update to 6.1.16 failed to properly install the Bridged driver, or some similar trouble happened.

Please report how Ping through NAT works.

[PhilMa]

Hi and thanks so much for your reply.
Ping through NAT works great. When I switch back to Bridged, the same issue persists.
It looks like my host machine is not passing traffic. The guest machine can ping the host, but nothing else. Not the default gateway, for example.

What should I check next? I'm continuing to troubleshoot too but am unsure what is required for Bridged networking to work properly.

[fth0]

You could provide a VBox.log file from a VM run with the failing setup, and you could create a Wireshark capture inside the host OS containing the working and not working pings.