This article I will show you how to install a Proxmox Virtual Environment (an open-source server virtualization management) and configure networking (Routed Configuration).

First of all, we need a server with OS Debian installed.

Proxmox VE installation

Enable repo.

# echo "deb buster pve-no-subscription" > /etc/apt/sources.list.d/pve-install-repo.list

Add a key.

# wget -O /etc/apt/trusted.gpg.d/proxmox-ve-release-6.x.gpg

Update the system.

# apt update
# apt upgrade
# apt dist-upgrade

Delete packages that we do not need.

# aptitude -q -y purge firmware-bnx2x firmware-realtek firmware-linux firmware-linux-free firmware-linux-nonfree

Install Proxmox VE.

# apt install proxmox-ve

After installation, we reboot the server and check if the proxmox kernel is loaded

# uname -rv
5.3.13-1-pve #1 SMP PVE 5.3.13-1 (Thu, 05 Dec 2019 07:18:14 +0100)

Check if the kvm module has been loaded.

# lsmod | grep kvm

kvm_intel 249856 6
kvm 655360 1 kvm_intel
irqbypass 16384 1 kvm

Network Configuration

Uncomment the line – net.ipv4.ip_forward = 1 in the file – /etc/sysctl.conf

Or run the following command to activate IP forwarding.

# sysctl -w net.ipv4.ip_forward=1

In my case, I have an additional subnet – and a separate IP –
When using a routed installation, you have to manually add the route to the virtual machine.
Open /etc/network/interfaces and add the following (do not touch the main IP settings)

auto vmbr1
iface vmbr1 inet static
   bridge_ports none
   bridge_stp off 
   bridge_fd 0
   bridge_maxwait 0
      up ip route add dev vmbr1
      up ip route add dev vmbr1
      up ip route add dev vmbr1

Next, when creating a virtual machine, select vmbr1 network interface.

An example of network settings in VM.



You have successfully installed Proxmox VE and configure networking.