two physical network cards as "net bridge"

[Tymothy Phil]

Hello, dear friends.

I have a host machine "Windows 10" and guest virtual machine Linux Debian on VirtualBox. There are two network cards in the host machine.
I need to throw both network cards into a virtual machine as separate devices.
I have activated two virtual adapters in the virtual machine network settings, each as a "network bridge".
Unfortunately, I could not get both adapters to work in the guest machine at the same time. When one of them is sucked, the second one necessarily turns off.
How do I make both adapters work simultaneously in the "network bridge" mode?

Yours faithfully,
Dmitriy

[socratis]

When one of them is sucked, the second one necessarily turns off.

Why does it not work? Who is not using your 2nd Bridged card. And why? I have a similar setup; one Thunderbolt-2-Ethernet and one WiFi. I bridge 2 NICs into two different cards. It works.

We're going to need to see a VM log from a complete VM run, with the 2 bridged adapters activated and connected:

• Start the VM from cold-boot (not from a paused or saved state) / Observe error / Shutdown the VM (force close it if you have to).
• With the VM completely shut down (not paused or saved), right-click on the VM in the VirtualBox Manager and select "Show Log".
• Save only the first "VBox.log", ZIP it and attach it to your response (see the "Upload attachment" tab below the reply form).

[Tymothy Phil]

When one of them is sucked, the second one necessarily turns off.

Why does it not work? Who is not using your 2nd Bridged card. And why? I have a similar setup; one Thunderbolt-2-Ethernet and one WiFi. I bridge 2 NICs into two different cards. It works.

I do not know what helped to correct the situation, but now both interfaces work. I created an additional profile, then deleted this profile, then rebooted, deleted all the network settings, got automatically, changed the settings of one of the interfaces - and voila, now both work in the "network bridge" mode ... however, I can not exactly state which physical network cards are used in each case, I do not understand in what order the virtual machine uses them ...

I would be extremely grateful for the clarification!

Yours faithfully,
Dmitriy

[socratis]

I can not exactly state which physical network cards are used in each case, I do not understand in what order the virtual machine uses them

In the order that you defined them perhaps? If the order of the adapters in your Win10 doesn't help, I'll use an example. Adjust the numbers/names to your scenario. From the VM settings, you get:

Adapter 1: Bridged to "en4: Thunderbolt",     MAC address: 080027796BCF
Adapter 2: Bridged to "en0: Wi-Fi (Airport)", MAC address: 080027C9021A

From the Win10 terminal (butchered output for brevity):

C:\Windows\System32>ipconfig /all
Ethernet adapter Bridged1:
   Physical Address. . . . . . . . . : 08-00-27-79-6B-CF
   IPv4 Address. . . . . . . . . . . : 192.68.3.119(Preferred)
Ethernet adapter Bridged2:
   Physical Address. . . . . . . . . : 08-00-27-C9-02-1A
   IPv4 Address. . . . . . . . . . . : 192.168.3.120(Preferred)

In your case, from the VBox.log, information again "chopped" for brevity:

00:00:02.734636 [/Devices/e1000/0/Config/] (level 4)
00:00:02.734641   MAC      <bytes>   = "08 00 27 d0 97 a3" (cb=6)
00:00:02.734649   Network  <string>  = "HostInterfaceNetworking-Qualcomm Atheros AR938x Wireless Network Adapter" (cb=73)

00:00:02.734667 [/Devices/e1000/1/Config/] (level 4)
00:00:02.734672   MAC      <bytes>   = "08 00 27 b6 fc 02" (cb=6)
00:00:02.734680   Network  <string>  = "HostInterfaceNetworking-Marvell Yukon 88E8056 PCI-E Gigabit Ethernet Controller" (cb=80)

The log can't show the acquired IP addresses for Bridged mode, but now you know what to look for. Check the output of your "ifconfig -a" from within your guest and look for those MAC addresses and make the connections...