Proxmox network config on Hetzner brings iface down


Nov 3, 2017
Hi there,
I need your help here... Server is at Hetzner, Proxmox 5.1 using single IPs - no subnet - with MAC adresses.

I currently use this interface config:

auto lo
iface lo inet loopback
iface lo inet6 loopback

auto enp0s31f6
iface enp0s31f6 inet static
    address <serverip>
    gateway <gatewayip>
    up route add -net <gatewayip but .0 is last number> netmask gw <gatewayip> dev enp0s31f6
auto vmbr0
iface vmbr0 inet static
    address  <serverip>
    netmask  <servernetmask>
    gateway  <servergateway>
    bridge_ports enp0s31f6
    bridge_stp off
    bridge_fd 0

The general network is okay but as soon as I add the vmbr0 config, the server boots but the interface enp0s31f6 (main network connection) doesn't come up anymore.

Can somebody help me with a valid configuration on Hetzner? I need a config that allows me to just add the MAC address in VM network settings and the VM then pulls the correct settings.

Your help is much appreciated.


Active Member
Nov 7, 2017
dont give your interface an adress.
your interface will be intiliazed but the bridge is getting the ip

except oyu wanna go routed but this aint gonna work.
routed is only if your subnet has public ips then your bridge would get that subnet and route trough your main ip

you would need to masquered it

if you have only one ip at hetzner you could run your eth0
as a single interface and your bridge without a bridgeport (it becomes kinda virtual bridge)
now you can portforward and masquered the shit outta that poor little ip

but its all already written here

keep in mind if you get a subnet form hetzner, you need to eitehr keep forwarding like with a single ip, or assign mac adresses of your vms to hetzner portal so their junipers dont panic


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