Proxmox on Hetzner with public IPs

Today we will learn to configure out Proxmox hypervisor on a rented server in Hetzner datacenter.

Proxmox need a special setup for public IPs because they filter traffic based on MAC address of physical host and a standard bridge is not enough. Also today we will configure a second linux bridge as a Private network because not all VMs need a public IP.

Configure Public IPs:

iface enp2s0 inet static
    address  [IP of physical server]
    netmask  255.255.255.255
    pointopoint [Gateway IP of physical server]
    gateway  [Gateway IP of physical server]
    post-up echo 1 > /proc/sys/net/ipv4/conf/enp2s0/proxy_arp

auto vmbr0
iface vmbr0 inet static
    address  [IP of physical server]
    netmask  255.255.255.255
    bridge_ports none
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

    # Repeat this line for each IP of extra subnet
    up route add -host [Extra public IP] dev vmbr0

Once configured our public network we will move forward to configure a private one.

Configure Private network:

auto vmbr2
iface vmbr2 inet static
    address 10.0.0.1
    netmask 255.255.255.0
    bridge_ports none
    bridge_stp off
    bridge_fd 0
    post-up   iptables -t nat -A POSTROUTING -s '10.0.0.0/24' -j MASQUERADE
    post-down iptables -t nat -D POSTROUTING -s '10.0.0.0/24' -j MASQUERADE

Using this setup you will be able to host VMs with both Public and Private IPs.

Due to latest bug in Proxmox you will also need to add a firewall rule to drop port 43 ad Datacenter level.

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