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Using ipv6 in cloud

IPv6 in Arbutus Cloud

IPv6 Link-Local (LLA) and Global Unicast Addresses (GUA) are generally available within the Arbutus cloud environment. GUA can be set up via a separate interface, which in turn also handles only the IPv6 traffic. Addresses are being set up using Stateless Address Auto Configuration (SLAAC), which automatically sets up the IP on the VM interface. By default, the security group rules will allow all outbound traffic from the VM via the IPv6 GUA, but no traffic that originates from outside the VM will be allowed until specific security group rules have been defined. This is the same behaviour as IPv4.

Example of an OpenStack CLI Configuration

Get the ID of the VM to attach the network interface.

openstack server list
+--------------------------------------+-----------------+---------+-----------------------------------------------+----------------------------------+----------+
| ID                                   | Name            | Status  | Networks                                      | Image                            | Flavor   |
+--------------------------------------+-----------------+---------+-----------------------------------------------+----------------------------------+----------+
| 74be352d-19ca-46cc-9661-7088d2652e34 | test            | ACTIVE  | def-bott-network=192.168.27.140, 206.12.93.29 | Debian-10.9.2-Buster-x64-2021-05 | p1-1.5gb |
+--------------------------------------+-----------------+---------+-----------------------------------------------+----------------------------------+----------+

Assign a new network interface to the VM, using IPv6 as network.

openstack server add network 74be352d-19ca-46cc-9661-7088d2652e34 IPv6-GUA

Check the status of the assignment.

openstack server list
+--------------------------------------+-----------------+---------+------------------------------------------------------------------------------------------------+----------------------------------+----------+
| ID                                   | Name            | Status  | Networks                                                                                       | Image                            | Flavor   |
+--------------------------------------+-----------------+---------+------------------------------------------------------------------------------------------------+----------------------------------+----------+
| 74be352d-19ca-46cc-9661-7088d2652e34 | test            | ACTIVE  | IPv6-GUA=2607:f8f0:c11:7004:f816:3eff:fef1:8cee; def-bott-network=192.168.27.140, 206.12.93.29 | Debian-10.9.2-Buster-x64-2021-05 | p1-1.5gb |
+--------------------------------------+-----------------+---------+------------------------------------------------------------------------------------------------+----------------------------------+----------+

Example of a Web Interface Configuration

Log into the dashboard and go to the Instances menu, then click on Attach Interface, which will open a dialog. From the network menu, select IPv6-GUA (2607:f8f0:c11:7004::/64) and click Attach. The IPv6 address is now available and can be used until the interface is detached. Every time the interface is detached, the GUA is released and put back into the pool and thus, can be used by anyone else. Rebuilding or restarting the VM however, will not release the GUA.

Access from any IPv6 GUA can be granted via Security Groups in OpenStack; the only difference is the CIDR which automatically detects the address type.

Example of a Debian or Ubuntu 26.04 Instance

When researchers launch an instance with the Debian or Ubuntu 26.04 operating system with the IPv6 network (i.e., IPv6-GUA), the selected SSH key pair will not install successfully. As a result, the researchers cannot ssh into the instance and will receive a Permission Denied error message instead. To work around the problem, when researchers are launching a new instance, they can create an initial user account by completing the following steps:

  1. To create a virtual machine, select Compute->Instances on the left menu, then click on the Launch Instance button.
  2. Follow the Cloud Quick Start Guide to complete the displayed form where you define your virtual machine.
  3. Select Configuration in the left menu.
  4. Add the following script to the Customization Script. Replace [username] with the researcher's preferred username and [public key] with the user's public key.
  5. Select Configuration Drive.
users:
  - name: [username]
    gecos: [username]
    groups: sudo
    sudo: ALL=(ALL) NOPASSWD:ALL
    shell: /bin/bash
    lock_passwd: true
    ssh_authorized_keys:
      - [public key]

ssh_pwauth: false

Example of a Linux Configuration

The OpenStack network you configured above will appear in Linux as an additional eth-type interface. In most cases, /dev/eth0 will be your existing interface. In most cases, your new IPv6 enabled interface will be /dev/eth1. The easiest way to pick-up your new device is to reboot. But first, check to confirm that IPv6 is enabled with this command

sudo sysctl -a | grep ipv6.*disable
The output should all end in zeros. IPv6 enabled is the default in all recent images. Any kernel parameters that need to be changed to zero should be added to /etc/sysctl.conf.

Also, add the following kernel parameters in /etc/sysctl.conf.

net.ipv6.conf.eth1.forwarding=0
net.ipv6.conf.eth1.accept_ra=1

Reboot your system and confirm IPv6 is enabled and that /dev/eth1 exists.

Next, add the following configurations to /etc/sysconfig/network-scripts/ifcfg-eth1

IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no

Reboot your system again. The /dev/eth1 interface should be configured and ready to be used.

You may then confirm the IPv6 configuration with

ip -6 address

Finally, confirm that IPv6 is working with

ping6 -c 1 www.google.com

That's all. Congratulations. Your system is now configured to use IPv6.

Further Reading