Proxmox 8: Fix Dependency Failed for networking.service Error

Agosto 7th, 2025

How to fix Proxmox 8 network “Dependency Failed for networking.service” Error

After installing or rebooting Proxmox 8, are you running into network issues or seeing the error “Dependency failed for networking.service”

This guide explains a specific cause of that error and how to fix it — particularly when it’s related to the ifupdown2-pre.service timeout that prevents the network from starting properly.

Note: This fix only applies if the issue is caused by ifupdown2-pre.service. If your network issue has a different root cause, the solution may not work.

Possible Cause: Boot Sequence Hangs Before Networking

Proxmox 8 uses a service called ifupdown2-pre.service, which runs during boot to wait until all hardware is fully initialized — especially network interfaces.

On some systems, this step can fail or timeout, often due to:

• A missing or slow-to-respond hardware device (e.g. a disk, USB NIC, virtual CD)
• Something in udev holding up the queue

When this happens, Proxmox skips the network startup, leaving the system offline.

One Way to Fix It: Mask the Problematic Pre-Service

1 – Log in locally (using a monitor and keyboard, KVM, or IPMI console)
2 – Try restarting the network manually:

systemctl restart networking.service

3 – Apply the permanent workaround:

systemctl mask ifupdown2-pre.service

4 – Reboot to confirm:

reboot

Important Notes

This workaround is safe for most setups, but it’s not the only cause of network issues in Proxmox 8.

If your NIC isn’t configured properly, or if your /etc/network/interfaces file is misconfigured, this fix won’t help.

You can always unmask the service later using:

systemctl unmask ifupdown2-pre.service

If you’re facing network issues on Proxmox 8, understanding the cause is key. This fix may help in certain cases, but always verify your system’s specific situation.

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If you are interested in learning how to setup ipv4 in ubuntu24.04.