IPv6

Current support for IPv6 in MAAS is similar to support for IPv4 but with the following caveats:

  • MAAS uses IPv4 for its internal operation (adding/deploying nodes).
  • IPv6 is only supported on networks where MAAS also manages IPv4 DHCP.
  • A node's network interface can be on only a single IPv6 subnet.
  • A rack controller's network interface can only manage a single IPv6 subnet.

A rack controller in an IPv6 context needs to have the region API server URL specified by hostname. See install a rack controller for details.

The web UI and the MAAS CLI (logging in to the API server) can be accessed in the same way on both IPv4 and IPv6. To use an IPv6 address in a URL surround it with square brackets. For example, on the local machine (::1, the IPv6 equivalent of localhost):

http://[::1]:5240/MAAS/

Note: Most BMCs can only be controlled over IPv4.

Enable IPv6

You enable IPv6 networking in the same way that you enable IPv4 networking: configure a separate rack controller interface for your IPv6 subnet, in addition to the one you need for your IPv4 subnet. The IPv6 interface must define a static address range. Provided that you already have a functioning IPv6 network, that's all there is to it. The following sections will go into more detail about what is supported, what is needed, and what to do if you don't yet have a functioning IPv6 network.

An IPv6 interface can use the same network interface on the rack controller as an existing IPv4 network interface. It just defines a different subnet, with IPv6 addressing. A node that's connected to the IPv4 subnet will also be connected to the IPv6 subnet on the same network segment.

Configure an IPv6 subnet

Define a reserved static IP range and nodes deployed on the subnet will get a static address in this range. Since IPv6 networks are normally 64 bits wide you can be generous with the range size. Leave the netmask and broadcast address fields blank.

You may want MAAS to manage DHCP and DNS, but it's not required. In fact nodes do not need a DHCP server at all for IPv6; MAAS configures static IPv6 addresses on a node's network interface while deploying it. A DHCPv6 server can provide addresses for containers or virtual machines running on the nodes, as well as devices on the network that are not managed by MAAS, but it is not needed for the nodes themselves. MAAS will not be aware of any addresses issued by DHCP, and does not guarantee that they will stay unchanged.

Routing

In IPv6, clients do not discover routes through DHCP. Routers make themselves known on their networks by sending out route advertisements. These RAs contain other configuration as well: whether clients should statelessly configure their own unique IP addresses based on their MAC addresses; whether they should request stateless configuration from a DHCP server; and finally, whether they should request a stateful IP address from a DHCP server. Since a network interface can have any number of IPv6 addresses even on a single subnet, several of these address assignment mechanisms can be combined.

However, when MAAS configures IPv6 networking on a node, it does not rely on RAs. It statically configures a node's default IPv6 route to use the router that is configured on the cluster interface, so that the node will know their default gateway. They do not need DHCP and will not autoconfigure global addresses.

However, if you are planning to operate DHCPv6 clients as well, e.g. on machines not managed by MAAS or on virtual machines hosted by MAAS nodes, you may still want to have RAs configured to make those clients obtain configuration over DHCP.

If you need RAs but your gateway does not send them, install and configure radvd somewhere on the network to advertise its route.