Configuration WIFI and Ethernet

[GB_Informatics]

Hello, I have installed Debian 12 with a graphical interface on a Lenovo computer on which proxmox is installed.
I would like the switch to the wifi connection to be made automatically on the PC if the RJ45 starts to malfunction in order to have remote access. I can't configure the /etc/network/interfaces file, each time I allow the whole connection.

Can someone please help me?

 

[BobhWasatch]

Most of the graphical desktops have built-in tools to configure wifi. However, most of them manage it using an automatic system like Network Manager rather than /etc/network/interfaces. They generally do avoid trying to manage interfaces configured in /etc/network/interfaces though so you can set it up manually if you want to.

The problem you are going to have with this fallback plan is that WiFi does not support bridging. So you can't use it with the default vmbr0 bridge setup to access your virtual machines, it will only work for the host. To give VM's access over WiFi you must set up NAT + port forwarding per the PVE manual. And doing that with 2 IP's on the same subnet is going to be tricky.

https://pve.proxmox.com/wiki/WLAN

 

[GB_Informatics]

The wifi would only be used to connect to the PC itself (not proxmox) to reboot the PC and restart everything.

Does xcp-ng do this?

 

[BobhWasatch]

What does that even mean, "connect to the PC itself, not Proxmox"? Are you running Proxmox under another Hypervisor or something? Could you clarify what your setup looks like?

 

[GB_Informatics]

Promox est installé sur un PC exécutant Debian 12 avec une interface utilisateur graphique. Le PC est compatible WIFI et Ethernet.
Le WIFI n'est pas utilisable pour Proxmox.
J'ai installé un logiciel de contrôle à distance pour intervenir au cas où, donc si pour une raison quelconque l'Ethernet ne fonctionne pas, j'aimerais qu'il bascule la connexion du PC en wifi, comme le fait Windows 10 par exemple.

 

[BobhWasatch]

I don't know how to make this work. You can set up WiFi using the graphical desktop. SSH should already be on there. But I don't know how to make it do this fallback automatically without some fairly complex setup. You can't just have two IP addresses.

Reason is with Linux the IP addresses are owned by the kernel as a whole, not by the interfaces. If you have two IP on the same subnet (e.g. 192.168.2.1/24 and 192.168.2.2/24), it is not predictable which one the kernel will use unless one of them is physically down (no-carrier or similar). If your WiFi and wired are on different subnets then it can work.

This is not specific to Proxmox.

If Windows 10 does what you want, why not use that?

 

[GB_Informatics]

Sans le script, la bascule automatique entre le wifi et l'ethernet fonctionne correctement à une condition, que l'interface vmbr0, correspondant à l'interface virtuelle de proxmox soit configurée dans /etc/network/interfaces