Hetzner Dedicated Server - Dual public IP setup


New Member
Oct 22, 2023
Hello my friends!

I have bought a Dedicated Server at Hetzner and ordered an additional IP address in order to have one for the Proxmox VE itself, and another for a VM I will create inside Proxmox VE.

Now, my problem is, I have tried for around 5-6 hours to use some instructions found on the internet ( e.g. , or e.g.2 ) but I did not manage to make a VM have internet access. Please, I am desperate, could someone help me?

In the following I will use:
<IP0> = Main IP of the server ( which I use to connect to Proxmox VE )
<IPV6> = Main ipv6 of the server
<IP1> = Secondary IP that I have bought
<GATEWAY0> = gateway ip indicated by Hetzner

After a fresh install of proxmox using installImage from Hetzner, my /etc/network/interfaces looks something like this:
# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!
source /etc/network/interfaces.d/*
auto lo
iface lo inet loopback
iface lo inet6 loopback
auto enp35s0
iface enp35s0 inet static
        address <IP0>/27
        gateway <GATEWAY0>
        up route add -net <aa.bb.cc ( identical with IP0)>.224 netmask gw <GATEWAY0> dev enp35s0
# route <aa.bb.cc ( identical with IP0)>.224/27 via <GATEWAY0>

iface enp35s0 inet6 static
        address <IPV6>/64
        gateway fe80::1

iface eth0 inet manual    # <- Topic Author comment: I think this is actually useless

Now, from what I understand, I am able to create a network like 192.168.100.x , which can have multiple machines that use my <IP0> as a "gateway", something like this:
auto vmbr0
iface vmbr0 inet static
        bridge-ports none
        bridge-stp off
        bridge-fd 0
        post-up   echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up   iptables -t nat -A POSTROUTING -s '' -o vmbr1 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s '' -o vmbr1 -j MASQUERADE

Then, can someone help me setup a network config file that has one "vmbr0" for example which allows a VM to have <IP1>, and a "vmbr1" which is a 'subnet' just like the one mentioned in the code right above this paragraph?
Last edited:

I have quite the same setup and gladly share my learnings. To be frank, it took me a while as well.
Don't forget to order custom MAC addresses from Hetzner for the 2nd-IP and subsequently configure the VM accordingly.
I shortend the config to show ipv4 only.

PVE config

auto lo
iface lo inet loopback

auto vmbr0
iface vmbr0 inet static
address MAINIP/27
bridge_ports eno1
bridge_stp off
bridge_fd 0
bridge_maxwait 0
up route add -net SUBIP netmask gw GATEWAYIP dev vmbr0

VM config
other NICID may apply

iface lo inet loopback
allow-hotplug ens18
iface ens18 inet static
address SUBIP/27



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