Configuring IPv6 on virtual machines with ESXi

Reviewed on 22 April 2024 • Published on 24 February 2022

esxi
virtual-machine
ubuntu

Important

Due to VMware’s acquisition by Broadcom, the free edition of VMware vSphere Hypervisor is no longer available on the VMware website. For more details, check out the EOL of free vSphere Hypervisor. Please note that the following content is provided as-is, without any guarantee of functionality. We suggest considering alternative hypervisors such as Proxmox. You can learn how to deploy virtual machines with Proxmox on Scaleway Dedibox.

This tutorial explains how to configure IPv6 on virtual machines on ESXi hypervisors.

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 SSH key
A Dedibox running ESXi 6.5 or later
Enabled SLAAC for your Dedibox
Requested an IPv6 prefix
Installed a virtual machine running Ubuntu 20.04 or later and configured a failover IPv4 on it

Log into your virtual machine using SSH.

Run the command ip a to display your current network configuration. The command returns an output as follows:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
   valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
   valid_lft forever preferred_lft forever
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 00:50:56:01:fa:b9 brd ff:ff:ff:ff:ff:ff
altname enp3s0
inet your.fail.over.ip/32 scope global ens160
   valid_lft forever preferred_lft forever
inet6 fe80::250:56ff:fe01:fab9/64 scope link
   valid_lft forever preferred_lft forever

Take note of the following information from the output above:

The name of the network interface (here ens160)
The local IPv6 of your VM (here fe80::250:56ff:fe01:fab9/64)

Open the file /etc/dhcp/dhclient6.conf in a text editor and edit it as shown below. Then save the file and quit the text editor.
```
interface "ens160" {
    send dhcp6.client-id DUID;
}
```
Important
Edit the name of the internet interface to one of your VMs and replace DUID with the DUID of your prefix.

Open the file /etc/systemd/system/dhclient.service in a text editor and edit it as shown below. Then save and exit the editor.

[Unit]
Description=dhclient for sending DUID IPv6
After=network-online.target
Wants=network-online.target
[Service]
Restart=always
RestartSec=10
Type=forking
ExecStart=/sbin/dhclient -cf /etc/dhcp/dhclient6.conf -6 -P -v eno1
ExecStop=/sbin/dhclient -x -pf /var/run/dhclient6.pid
[Install]
WantedBy=network.target

Enable the service to start automatically after each reboot of the machine. Then start the service manually for the first time.

systemctl enable dhclient.service
systemctl start dhclient.service

Verify that the service is running with the following command:

systemctl status dhclient.service

The command above returns an output as follows:

    ● dhclient.service - dhclient for sending DUID IPv6
    Loaded: loaded (/etc/systemd/system/dhclient.service; enabled; vendor pres>
    Active: active (running) since Thu 2022-02-24 12:18:03 UTC; 27min ago
  Main PID: 5342 (dhclient)
    Tasks: 4 (limit: 4627)
    Memory: 1.6M
    CPU: 23ms
    CGroup: /system.slice/dhclient.service
            └─5342 /sbin/dhclient -cf /etc/dhcp/dhclient6.conf -6 -P -v ens160

Edit your Netplan configuration file (probably located at /etc/netplan/01-netcfg.yaml) and edit it as follows:
```
network:
version: 2
renderer: networkd
ethernets:
    ens160:
    dhcp4: false
    dhcp6: false
    addresses:
    - FAILOVER_IP/32
    - IP_FROM_YOUR_PREFIX/SUBNET
    gateway4: 62.210.0.1
    gateway6: LOCAL_IPv6
    nameservers:
        addresses: [ "51.159.47.28", "51.159.47.26" ] # Replace the IP of the DNS cache server with the one located in the same physical location as your machine for optimal performances (https://www.scaleway.com/en/docs/console/account/reference-content/scaleway-network-information/#dns-cache-servers/)
    routes:
    - to: 0.0.0.0/0
        via: 62.210.0.1
        on-link: true
    - to: "::/0"
        via: "LOCAL_IPv6"
        on-link: true
```

Apply the new network configuration with the following command:

netplan apply

You now have configured the IP address, but the IPv6 connectivity is not working yet.

Find the gateway for your prefix by running the following command:

ip -6 route

The command returns an output as follows:

::1 dev lo proto kernel metric 256 pref medium
YOUR_IPv6_PREFIX/SUBNETMASK dev ens160 proto kernel metric 256 pref medium
fe80::/64 dev ens160 proto kernel metric 256 pref medium
default via fe80::7a0c:f0ff:fedf:254d dev ens160 proto static metric 1024 onlink pref medium

Take note of the default gateway (here fe80::7a0c:f0ff:fedf:254d).

Edit your Netplan configuration file again and modify it as follows:

gateway6: DEFAULT_GATEWAY
- to: "::/0"
    via: "DEFAULT_GATEWAY"
    on-link: true

Note

Remember to replace DEFAULT_GATEWAY with the default gateway found in the previous step.

Reload your network configuration for the last time:

netplan apply

You have now IPv6 connectivity for your virtual machine. You can test it by running a ping6: ping ipv6.google.com.