VirtualBox 7.x + | DNS / Name resolution problem

[carcap]

When trying to install a VM with Linux as guest OS under VirtualBox 7.x, the installation fails at the name resolution of the online repo. This was tested with Debian and Arch Linux. The installation gives an error at the moment when the name resolution to the repo is needed. To exclude an error in the images, Debian was installed from a full image, for this no online repo is necessary during the installation. In the freshly started OS, however, the error of the non-existent name resolution occurs again, SSH via port forwarding does not work either. A ping to "google.de" is unsuccessful. A ping to "8.8.8.8", is successful. During the installation all default values of the installer were taken over.

When performing the same installations on VirtualBox 6.1.42, this error does not occur and the name resolution works, likewise SSH works without problems.

Host: Windows 10 Pro 22H2

Guest: Debian Stable Bullseye 11.6.0 (Kernel 5.10) Arch Linux Rolling (Kernel 6.1)

[fth0]

In the VM's configuration, you've chosen the PCnet-FAST III (Am79C973) virtual network adapter. You could try if using the Intel PRO/1000 MT Desktop (82540EM) virtual network adapter makes a difference.

[carcap]

This is at most a workaround, but not a final solution. The FastEthernet-NIC from AMD is in the list, so it should work in the new VB version. It is also in VB 6.1.42. I use this NIC to limit the machines to 100 Mbit/s without making complex settings on the OS. So it is a quite reasonable scenario to use this NIC.

[fth0]

Above all, this is a test if the issue somehow depends on the virtual networking hardware.

I use this NIC to limit the machines to 100 Mbit/s

How are you doing this? I'm asking because in my company setup with 850 Mbit/s, with the virtual Intel NIC I get > 350 MBit/s, and with the virtual PCnet NIC I get > 250 Mbit/s. And AFAIK, VirtualBox does not limit the bandwidth downstream at all.

[carcap]

The "AMD PCNet FAST III (Am79C973)" is physically a FastEthernet-NIC (max. 100Mbit/s) ​https://www.amd.com/system/files/TechDocs/21510.pdf and as such it is emulated, this NIC is set on my machines and I have exactly max. 100Mbit/s (12,5MB/s) on every machine with this NIC. The hardware in the backend can't be the reason, because machines with the emulated Intel-1000-NIC get higher speeds (up to 1Gbit/s).

[fth0]

VirtualBox also cannot be the reason IMO.

Perhaps your guest OS thinks to know that the NIC is limited to 100 Mbit/s and limits the traffic itself. I'm using Kali Linux (Debian) without any special configuration, BTW.