MAAS streamlines machine management with some custom networking
features, reducing user errors and manual tasks. Key optimizations
include:
- Network Discovery: Automatically detects and logs all visible
network devices, allowing optional enlistment into MAAS. - DHCP: Provides a next-server address for machines to PXE boot from a
local Network Boot Package (NBP). - DNS: Updates entries in real-time as machines change states.
- NTP: Locally controlled for precise timekeeping.
- Fabrics: Group VLANs for bulk operations.
- VLANs: Can be dynamically redefined in real-time.
- Subnets: Administrators can manage them locally.
- Other customizations: MAAS provides some specialty tools.
Integrating legacy network services (e.g, corporate DNS) is sometimes
possible but not recommended.
Network discovery
Network discovery passively detects devices on connected IPv4 subnets,
automatically identifying both deployable and non-deployable hardware
without manual input. Discovered devices appear on the dashboard,
displaying any advertised hostnames via mDNS (e.g., Avahi or Bonjour),
aiding in identification. Administrators can then choose to manage these
devices within MAAS by enlisting them.
DHCP
MAAS integrates DHCP services to streamline machine provisioning,
automating IP address allocation and network boot configurations. By
setting the next-server parameter, MAAS directs machines to the
appropriate TFTP server for PXE booting, ensuring efficient deployment.
When incorporating external DHCP servers, it's crucial to configure
them to provide the correct boot parameters, such as the next-server
address pointing to the MAAS server. This setup allows MAAS to manage
machine deployments effectively without IP conflicts.
MAAS also supports DHCP relays, enabling centralized DHCP management
across different VLANs or subnets. By forwarding DHCP requests to the
MAAS-managed DHCP server, administrators can maintain consistent network
configurations across complex topologies.
There's a lot more to be said about DHCP in MAAS. For a more
comprehensive understanding, refer to <link here>.
DNS
MAAS dynamically updates DNS entries based on machine state
(commissioned, deployed, released), automatically removing stale
records. Reverse DNS (PTR) and forward (A) records are generated for
subnets and VLANs, mapping machine IPs and hostnames consistently.
MAAS offers recursive DNS, forwarding external queries upstream while
controlling internal zones (e.g., myinternal.maas) to prevent internal
records from leaking. Machines get hostnames based on customizable
naming schemes, though manual assignment is supported. Administrators
can also set custom TTL values to control DNS record caching behavior.
NTP
MAAS uses Chrony to synchronize time across region and rack controllers,
to coordinated operations and maintain accurate logs. Rack controllers
provide NTP settings via DHCP, so deployed machines automatically
receive the right time.
Administrators can customize NTP servers, though the region controller
defaults to ntp.ubuntu.com. Region controllers sync with external NTP
sources, while rack controllers sync with region controllers. This keeps
time consistent within the MAAS envelope. External-only NTP syncing is
also an option.
Fabrics
A fabric is a logical construct that groups VLANs that share network
infrastructure. This allows administrators to organize manage multiple
VLANs under a single entity. Fabrics create proper isolation while
maintaining communication, so scaling and maintenance are easier.
VLANs and subnets
VLANs and subnets are embedded into the provisioning workflow, so tagged
and untagged VLANs, as well as subnets contained within them, can be
managed from a single interface. A clean, clear interface ensures the
correct network settings, which in turn reduces errors.
Other customizations
Network validation
MAAS can validate connectivity and speed on network connections prior to
deployment.
Static routes
MAAS can define global static routes globally to prevent drift, and to
help improve security, redundancy, and performance.
Loopback interfaces in MAAS-managed environments
Loopback interfaces are necessary for BGP and FRR, but tricky to
configure. MAAS provides the capability to centrally define and
configure loopback interfaces directly.
Bridges
MAAS offers centralized bridge management, automatically integrated with
VLANs and bonds.
Note that while Netplan provides a simpler way to configure bridges
manually (through YAML files), MAAS-managed bridges don't require
manual configuration. In some cases, though, such as integrating
MAAS-managed systems into external environments, Netplan is the right
answer.
Multi-NIC configurations
MAAS automatically detects and configures all available interfaces,
including multi-NIC machines.
Gateways
MAAS centralizes gateway configuration across all connected machines.
Bonds
Network bonding is common in high-availability environments, so MAAS
bond management via the UI or CLI. MAAS supports a wide range of bonding
modes, such as active-backup or balance-rr.
Static IPs
MAAS allows administrators to define static IPs during machine
deployment. You can allocate from a pool or manually assign them.
There are other less tangible benefits of custom network integration,
but these depend on the use case.