Networking

MAAS 1.9 adds support for the modelling of a wide variety of networking concepts and configurations.

Networking Concepts

At a high level, MAAS supports the following networking concepts:

Fabrics

A fabric is a set of interconnected VLANs that are capable of mutual communication. A fabric can be thought of as a logical grouping in which VLANs can be considered unique.

For example, a distributed network may have a fabric in London containing VLAN 100, while a separate fabric in San Francisco may contain a VLAN 100, whose attached subnets are completely different and unrelated.

A "Default Fabric" is created when MAAS is installed (or upgraded).

Subnets

A subnet is a "layer 3" network defined by a particular network prefix, plus a network mask length (in bits). This notation is also referred to as a CIDR.

MAAS supports IPv4 and IPv6 subnets.

Examples:

10.0.0.0/8
172.16.0.0/12
192.168.0.0/16
2001:db8:4d41:4153::/64

Subnets can be annotated with a descriptive name, their default gateway, and/or their DNS server(s).

A subnet can be in a single space.

Subnets are considered managed if a cluster interface specifies the cluster network range.

VLANs

VLANs (Virtual LANs) are a common way to create logically separate networks using the same physical infrastructure.

Managed switches can assign VLANs to each port in either a "tagged" or an "untagged" manner. A VLAN is said to be "untagged" on a particular port when it is the default VLAN for that port, and requires no special configuration in order to access.

"Tagged" VLANs (traditionally used by network administrators in order to aggregate multiple networks over inter-switch "trunk" lines) can also be used with nodes in MAAS. That is, if a switch port is configured such that "tagged" VLAN frames can be sent and received by a MAAS node, that MAAS node can be configured to automatically bring up VLAN interfaces, so that the deployed node can make use of them.

A "Default VLAN" is created for every Fabric, to which every new VLAN-aware object in the fabric will be associated to by default (unless otherwise specified).

Spaces

A Space is a logical grouping of subnets that should be able to communicate with each other. Subnets within each space need not belong to the same fabric. For example, you may have a "DMZ" space in both your London and San Francisco fabrics, and a "Storage" space to indicate subnets attached to your storage network.

A "space-0" is created when MAAS is installed (or upgraded), which every subnet will belong to by default (unless otherwise specified).

Interfaces

Physical

After a node is commissioned, MAAS discovers its physical interfaces. In addition, devices are created with physical interfaces.

Prior to deployment, a MAAS administrator can specify additional interfaces to be configured on the node, including one or more of the below types.

Bond

A bond interface is capable of aggregating two or more physical interfaces into a single logical interface. Bonds can be used in conjunction with a managed switch (using Link Aggregation and Control Protocol, or LACP), or independently (software bonds).

VLAN

A VLAN interface can be used to connect to a tagged VLAN, if the switch port the node is connected to is authorized to access it.

Unknown

Unknown interfaces cannot be created by users.

Sometimes, unknown interfaces are discovered by MAAS. (For example, when MAAS learns of a new DHCP lease that is not associated with any known node or device.)

How to Configure Nodes for Networking

Creating a Bond Interface

Use the node-interfaces create-bond API to create a bond. For example:

maas admin node-interfaces create-bond node-d83ce230-4b50-11e5-a267-00163eb185eb name=bond0 vlan=0 parents=30 parents=31 mac_address=00:50:56:2b:60:53

Will produce output similar to the following:

    Success.
    Machine-readable output follows:
    {
        "name": "bond0",
        "links": [],
        "tags": [],
        "vlan": {
            "id": 0,
            "resource_uri": "/MAAS/api/1.0/fabrics/0/vlans/0/",
            "name": "Default VLAN",
            "vid": 0,
            "fabric": "fabric-0"
        },
        "enabled": true,
        "id": 41,
        "parents": [
            "eth0",
            "eth1"
        ],
        "mac_address": "00:50:56:2b:60:53",
        "type": "bond",
        "children": [],
        "resource_uri": "/MAAS/api/1.0/nodes/node-d83ce230-4b50-11e5-a267-00163eb185eb/interfaces/41/"
    }

Note that in the example above, the bond contains two interfaces because the parents parameter was specified twice, such as parents=30 parents=31.

Creating a VLAN Interface

To create a VLAN interface, use the node-interfaces create-vlan API.

Be aware that the vlan paremeter does not indicate a VLAN ID that corresponds to the VLAN tag. You must first create the VLAN, and then associate it with the interface. For example:

maas admin vlans create 0 name="Storage network" vid=100

The output will look similar to the following:

    Success.
    Machine-readable output follows:
    {
        "id": 1,
        "resource_uri": "/MAAS/api/1.0/fabrics/0/vlans/1/",
        "name": "Storage network",
        "vid": 100,
        "fabric": "fabric-0"
    }

Note that the 0 in the command above indicates the fabric_id. If you have not defined any additional fabrics, the fabric_id of the default fabric will be 0.

Now that a VLAN is created, it may be associated with a new interface:

maas admin node-interfaces create-vlan node-d83ce230-4b50-11e5-a267-00163eb185eb vlan=1 parent=30

With the following output:

    Success.
    Machine-readable output follows:
    {
        "name": "eth0.100",
        "links": [],
        "tags": [],
        "vlan": {
            "id": 1,
            "resource_uri": "/MAAS/api/1.0/fabrics/0/vlans/1/",
            "name": "Storage network",
            "vid": 100,
            "fabric": "fabric-0"
        },
        "enabled": true,
        "id": 44,
        "parents": [
            "eth0"
        ],
        "mac_address": "00:50:56:2b:60:53",
        "type": "vlan",
        "children": [],
        "resource_uri": "/MAAS/api/1.0/nodes/node-d83ce230-4b50-11e5-a267-00163eb185eb/interfaces/44/"
    }

Deleting an Interface

To delete an interface, use the node-interface delete API. For example:

maas admin node-interface delete node-d83ce230-4b50-11e5-a267-00163eb185eb 41

The output will report Success.