How to configure IPv6 virtual machines with Proxmox on Elastic Metal

Reviewed on January 30, 2025

When you install your server with a virtualization solution like Proxmox, you can create multiple virtual machines on the physical server and configure them to use flexible IPv6 addresses.

This guide covers the steps for configuring the network interfaces on different distributions inside a virtual machine on a Proxmox host using flexible IPv6 addresses on Elastic Metal servers.

Tip

The DNS cache server (nameserver) may vary depending on the physical location of your server. Refer to our network information documentation to find the IPv6 addresses to use with your machine.

Before you start

To complete the actions presented below, you must have:

A Scaleway account logged into the console
Owner status or IAM permissions allowing you to perform actions in the intended Organization
An Elastic Metal server with a hypervisor (Proxmox) installed
A flexible IPv6
A virtual MAC address

Finding your IPv6 gateway

Log into the virtual machine using SSH.
Identify the network interface:
```
ip a
```
Take note of the interface name (e.g., ens18).
Find the IPv6 gateway:
```
ip -6 route
```
Look for the line specifying the default route:
```
default via fe80::xxxx:xxxx:xxxx:xxxx dev ens18 proto static metric 1024 onlink
```
The fe80::xxxx:xxxx:xxxx:xxxx part is the link-local IPv6 gateway address.

Ubuntu - Configuration with Netplan

Open the Netplan configuration file:
```
sudo nano /etc/netplan/01-netcfg.yaml
```

Configure the network settings:

network:
  version: 2
  renderer: networkd
  ethernets:
    ens18:
      dhcp4: false
      dhcp6: false
      accept-ra: no
      addresses:
        - FLEXIBLE_IPv4/32
        - "FLEXIBLE_IPv6/64"
      routes:
        - to: 0.0.0.0/0
          via: 62.210.0.1
          on-link: true
        - to: "::/0"
          via: "LINK_LOCAL_IPv6_GATEWAY"
          on-link: true
      nameservers:
        addresses:
          - 51.159.47.28
          - 51.159.47.26

Replace the placeholders with actual values.

Apply the configuration:
```
sudo netplan apply
```

Debian

Edit the network interfaces file:
```
sudo nano /etc/network/interfaces
```

Configure the network interface:

auto ens18
iface ens18 inet static
  address FLEXIBLE_IPv4
  netmask 255.255.255.255
  gateway 62.210.0.1
iface ens18 inet6 static
  address FLEXIBLE_IPv6
  netmask 64
  gateway LINK_LOCAL_IPv6_GATEWAY

Set the DNS resolver:
```
sudo nano /etc/resolv.conf
```

Add the following lines:

nameserver 51.159.47.28
nameserver 51.159.47.26

Activate the network configuration:
```
sudo ifup ens18
```

CentOS

Edit the network script file:

sudo nano /etc/sysconfig/network-scripts/ifcfg-ens18

Configure the network interface:

DEVICE=ens18
BOOTPROTO=none
ONBOOT=yes
USERCTL=no
IPV6INIT=yes
PEERDNS=yes
TYPE=Ethernet
NETMASK=255.255.255.255
IPADDR=FLEXIBLE_IPv4
IPV6ADDR=FLEXIBLE_IPv6
GATEWAY=62.210.0.1
DNS1=51.159.47.28
DNS2=51.159.47.26
ARP=yes
HWADDR=virtual:mac:address

Enable the network interface:
```
sudo ifup ens18
```

Debugging Configuration Issues

If your IPv6 configuration does not work, try the following:

Check the interface configuration:
```
ip a
ip route
ip -6 route
```
Run a ping test:
```
ping -6 google.com
```
Verify DNS resolution:
```
dig google.com
dig -6 google.com
```

Check firewall settings:

sudo iptables -L -v -n
sudo ip6tables -L -v -n

Restart network services:
```
sudo systemctl restart systemd-networkd
```

Verify the link-local address:

ip -6 addr show dev ens18
ping -6 LINK_LOCAL_IPv6_GATEWAY