ubuntu 24.04 LTS has no network connection

[R4LF]

Host: Windows 10, Windows 11
VBox: 7.0.18, 7.0.20
Guest: ubuntu/xubuntu/lubuntu 24.04 LTS

Problem: No network. Host is connected, guest is set to "NAT", network is enabled, but there is no connection.

22.04 LTS/22.10/23.04/23.10 is working well, but after upgrading to 24.04 there is no network connection anymore.
An existing VM with "earlier than 24.04", previously well connected, started from 24.04 live CD, has network enabled but no connection, see picture.

2404nonetwork.png (213.05 KiB) Viewed 2444 times

I tried this in two locally different infrastructures, so it is not ISP/firewall/router/host.

[multiOS]

Have you checked the Network Settings entries in the VirtualBox Manager? Is the Cable Connected Box enabled (ticked)?

[R4LF]

Cable connected is enabled [x]
User interface ststus line shows "connected" icon.
Everything is connected.
Any guest <24.04 is connected.
Upgrading a connected guest < 24.04 to 24.04 breaks connection of the guest OS. VM is indicated as connected, but incoming and outgoing hangs on 0 bytes and guest OS says "not connected".

[R4LF]

Creating new VM offers "Type" Linux but "Version" list ubuntu ends with "Ubuntu 23.04". No 23.10 and no 24.04....
Tried with ubuntu server 24.04 on a VM "Other Linux (64-bit)" with "network bridge".
Installation worked well, but after reboot, system stuck at "Job systemd-network-wait-online.service/start running (...)", which means it has no configured network connection.

Is it possible that *ubuntu* 24.04 is not supported by VirtualBox 7.0.20 ?

[multiOS]

It's not listed as a supported Host or Guest version in the VirtualBox User Manual (7.0.20) but that does not necessarily mean that it won't work and I'm sure that there would be a significant number of reports on the Forum and in the Bugtracker if many users were seeing the same problem.

I don't use Ubuntu, but do have a Linux Mint 22 VM, which is said to be based on Ubuntu 24.04 LTS and that installed without any problem for me. There is always the possibility of "bridged mode" not working, depending on the network adapter hardware used and if there's a wireless connection involved. An explanation of that problem can be seen in this Forum Guide: viewtopic.php?f=35&t=96608#p468775

[R4LF]

My latest findings:

LMDE 6 is working well. It is based on debian 12 and this uses kernel 6.1.

ubuntu 24.04 (and all flavors, including Linux Mint 22 Wilma) uses kernel 6.8.
All my hosts, where I cannot make it with 24.04 / 6.8 guests, are several years old.
So probably it is an issue with unsupported CPU or network device by kernel 6.8...?

[multiOS]

If all of your Hosts which display the problem have the same CPU (and especially if it's a relatively 'new' release) it might be worthwhile reporting on the Public Bugtracker - https://www.virtualbox.org/wiki/Bugtracker - It's possible to search the open tickets for similar problems that have already been reported. According to the VirtualBox Changelogs - https://www.virtualbox.org/wiki/Changelog - "initial support" for Kernel 6.8 and 6.9 was implemented with the 7.0.16 release.

FYI Ubuntu 24.04 is shown as a "Supported Host Version" in the VirtualBox User Manual which comes with the recently released VirtualBox 7.1 BETA.