How to manage machine interfaces (snap/3.1/UI)

2.9 3.0 3.1
DEB CLI ~ UI CLI ~ UI CLI ~ UI
SNAP CLI ~ UI CLI ~ UI CLI ~ UI

This article will explain the following procedures related to machine interfaces:

How to edit machines interfaces

From a machine’s “Interfaces” page, click the menu icon for the interface to be edited and select “Edit Physical” from the resulting menu:

The following window will appear:

Four modes determine how a subnet address is assigned when MAAS deploys the machine. You can select one of these modes by clicking on the “IP mode” drop-down menu.

  • Auto assign: MAAS will assign a random static address (iface eth0 inet static). The pool of available addresses depends on whether the subnet is managed or unmanaged (see Subnet management).

  • Static assign: The administrator will specify a static address using a secondary field.

  • DHCP: The machine leases a dynamic IP address, via either MAAS-managed DHCP or an external DHCP server.

  • Unconfigured: The interface is not configured.

Press the “Save” button to apply the changes.

See Concepts and terms for the definitions of reserved range types.

How to create a bond interface

A bond is created by selecting more than one interface and clicking the now-active “Create bond” button:

After clicking the “Create bond” button, the bond configuration pane will appear.

From the bond configuration pane, you can rename the bond, select a bond mode (see below), assign a MAC address to the aggregate device and attach one or more tags.

The interfaces aggregated into the bond interface are listed below the “Tags” field. Use the “Primary” column to select the interface to act as the primary device.

You can select from the following bonding modes on the “Bond mode” drop-down menu:

  • balance-rr: Transmit packets in sequential order from the first available slave through to the last. This mode provides load balancing and fault tolerance.

  • active-backup: Only one slave in the bond is active. A different slave becomes active if, and only if, the active slave fails. The bond’s MAC address is externally visible on only one port (network adaptor) to avoid confusing the switch.

  • balance-xor: Transmit based on the selected transmit hash policy. The default policy is simple, which means that an XOR operation selects packages. This XOR compares the source MAC address and the resultant XOR between the destination MAC address, the packet type identifier, and the modulo slave count.

  • broadcast: Transmit everything on all slave interfaces. This mode provides fault tolerance.

  • 802.3ad: Creates aggregation groups that share the same speed and duplex settings. This mode utilises all slaves in the active aggregation, following the IEEE 802.3ad specification.

  • balance-tlb: Adaptive transmit load balancing, channel bonding that does not require any special switch support.

  • balance-alb: Adaptive load balancing, includes balance-tlb plus receive load balancing (rlb) for IPV4 traffic. This mode does not require any special switch support. ARP negotiation achieves load balancing in this case.

Press the “Save” button when you’re done.

The MAC address defaults to the MAC address of the primary interface.

How to create a bridge interface

Press the “Save” button when you’re done.

How to delete an interface

An interface can only be deleted via the MAAS CLI.

The “delete” command can be used to delete a bridge interface, a bond interface or a physical interface:

maas $PROFILE interface delete $SYSTEM_ID $IFACE_ID

For example:

maas admin interface delete 4efwb4 15

The following is output after the successful deletion of an interface:

Success.
Machine-readable output follows:

Note that while the label is presented, there is no machine-readable output expected after the successful execution of the delete command.

How to assign a network interface to a fabric

A network interface may be assigned to a fabric with the MAAS CLI only.

This task is made easier with the aid of the jq utility. It filters the maas command (JSON formatted) output and prints it in the desired way, which allows you to view and compare data quickly. Go ahead and install it:

sudo apt install jq

In summary, MAAS assigns an interface to a fabric by assigning it to a VLAN. First, we need to gather various bits of data.

List some information on all machines:

maas $PROFILE machines read | jq ".[] | \
    {hostname:.hostname, system_id: .system_id, status:.status}" --compact-output

Example output:

{"hostname":"machine1","system_id":"dfgnnd","status":4}
{"hostname":"machine2","system_id":"bkaf6e","status":6}
{"hostname":"machine4","system_id":"63wqky","status":6}
{"hostname":"machine3","system_id":"qwkmar","status":4}

You can only edit an interface when the corresponding machine has a status of ‘Ready’. This state is numerically denoted by the integer ‘4’.

List some information for all interfaces on the machine in question (identified by its system id ‘dfgnnd’):

maas $PROFILE interfaces read dfgnnd | jq ".[] | \
    {id:.id, name:.name, mac:.mac_address, vid:.vlan.vid, fabric:.vlan.fabric}" --compact-output

Example output:

{"id":8,"name":"eth0","mac":"52:54:00:01:01:01","vid":0,"fabric":"fabric-1"}
{"id":9,"name":"eth1","mac":"52:54:00:01:01:02","vid":null,"fabric":null}

List some information for all fabrics:

maas $PROFILE fabrics read | jq ".[] | \
    {name:.name, vlans:.vlans[] | {id:.id, vid:.vid}}" --compact-output

Example output:

{"name":"fabric-0","vlans":{"id":5001,"vid":0}}
{"name":"fabric-1","vlans":{"id":5002,"vid":0}}
{"name":"fabric-2","vlans":{"id":5003,"vid":0}}

This example will show how to move interface ‘8’ (on machine ‘dfgnnd’) from ‘fabric-1’ to ‘fabric-0’. Based on the gathered information, this will consist of changing the interface’s VLAN from ‘5002’ to ‘5001’:

maas $PROFILE interface update dfgnnd 8 vlan=5001 >/dev/null

Verify the operation by relisting information for the machine’s interface:

maas $PROFILE interfaces read dfgnnd | jq ".[] | \
    {id:.id, name:.name, mac:.mac_address, vid:.vlan.vid, fabric:.vlan.fabric}" --compact-output

The output shows that the interface is now on fabric-0:

{"id":8,"name":"eth0","mac":"52:54:00:01:01:01","vid":0,"fabric":"fabric-0"}
{"id":9,"name":"eth1","mac":"52:54:00:01:01:02","vid":null,"fabric":null}

How to discover interface identifiers

Interface identifiers can only be discovered via the MAAS CLI.

The MAAS CLI uses a numeric interface identifier for many interface operations. Use the following command to retrieve the identifier(s):

maas $PROFILE interfaces read $SYSTEM_ID

Look for either id or the number at the end of an interface’s resource URI, such as 15 in the following example output:

"id": 15,
"mac_address": "52:54:00:55:06:40",
...
"name": "ens9",
...
"resource_uri": "/MAAS/api/2.0/nodes/4efwb4/interfaces/15/"

How to create a VLAN interface

VLAN interfaces can only be created via the MAAS CLI.

To create a VLAN interface, use the following syntax:

maas $PROFILE vlans create $FABRIC_ID name=$NAME vid=$VLAN_ID

For example, the following command creates a VLAN called 'Storage network:

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

The above command generates the following output:

Success.
Machine-readable output follows:
{
    "vid": 100,
    "mtu": 1500,
    "dhcp_on": false,
    "external_dhcp": null,
    "relay_vlan": null,
    "name": "Storage network",
    "space": "undefined",
    "fabric": "fabric-0",
    "id": 5004,
    "primary_rack": null,
    "fabric_id": 0,
    "secondary_rack": null,
    "resource_uri": "/MAAS/api/2.0/vlans/5004/"
}

Be aware that the $VLAN_ID parameter 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:

maas $PROFILE interfaces create-vlan $SYSTEM_ID vlan=$OUTPUT_VLAN_ID \
parent=$IFACE_ID

OUTPUT_VLAN_ID corresponds to the id value output when MAAS created the VLAN.

The following example contains values that correspond to the output above:

maas admin interfaces create-vlan 4efwb4 vlan=5004 parent=4

The above command generates the following output:

Success.
Machine-readable output follows:
{
    "tags": [],
    "type": "vlan",
    "enabled": true,
    "system_id": "4efwb4",
    "id": 21,
    "children": [],
    "mac_address": "52:54:00:eb:f2:29",
    "params": {},
    "vlan": {
        "vid": 100,
        "mtu": 1500,
        "dhcp_on": false,
        "external_dhcp": null,
        "relay_vlan": null,
        "id": 5004,
        "secondary_rack": null,
        "fabric_id": 0,
        "space": "undefined",
        "fabric": "fabric-0",
        "name": "Storage network",
        "primary_rack": null,
        "resource_uri": "/MAAS/api/2.0/vlans/5004/"
    },
    "parents": [
        "ens3"
    ],
    "effective_mtu": 1500,
    "links": [
        {
            "id": 55,
            "mode": "link_up"
        }
    ],
    "discovered": null,
    "name": "ens3.100",
    "resource_uri": "/MAAS/api/2.0/nodes/4efwb4/interfaces/21/"
}

How to delete a VLAN interface

VLAN interfaces can only be deleted via the MAAS CLI.

The following command outlines the syntax required to delete a VLAN interface from the command line:

maas $PROFILE vlan delete $FABRIC__ID $VLAN_ID

Using the values from previous examples, you executed this step as follows:

maas admin vlan delete 0 100