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Networking

This section covers how a device connects to the network and to the SPEKTRA Edge platform: how you describe network configuration, how the device falls back between connections, how to route through a proxy, what the device needs to reach on the network, and how time is kept in sync.

Network configuration model

Device networking is described as a Netplan-format YAML document. This is a clean, declarative way to configure wired, Wi-Fi, and cellular connections, as well as advanced setups such as bonds, bridges, VLANs, and tunnels.

You can supply the network configuration when you create an install image (so the device has connectivity from first boot) and you can update it later from the dashboard. When you push configuration from the platform, you choose how it combines with what is already on the device:

Mode Behavior
Merge The pushed configuration is merged with the device’s existing configuration.
Replace The pushed configuration replaces the device’s existing configuration.

The device reports its observed network state back to the platform — active interfaces, IP addresses, and carrier information — which you can view on the device overview page.

Wired, Wi-Fi, and cellular

All three connection types are configured through the same network configuration document:

  • Wired connections typically use DHCP by default and need no configuration to come up.
  • Wi-Fi connections are configured with the network name and credentials.
  • Cellular connections are configured for the modem; a device can also be associated with a SIM in the platform for inventory and activation tracking.

See the Netplan documentation for the exact YAML for each type.

Connection fallback

A field device often has more than one way to reach the network, and its configuration can be changed remotely. To keep a configuration mistake or a link outage from taking a device permanently offline, the OS has several layers of fallback — network configuration fallback, uplink (interface and cellular) failover, and proxy fallback. These are covered in detail on the Connection fallback page.

In this section

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Connection fallback

Devices are often deployed where connectivity is imperfect: a misapplied network change, a flaky uplink, or a proxy that goes down. SPEKTRA Edge OS has several fallback behaviors that keep a device reachable and recoverable. This page explains the three that matter most: network configuration fallback, uplink (interface and cellular) failover, and proxy fallback.

Network configuration fallback

When you push a new network configuration to a device, there is always a risk that the new configuration is wrong and takes the device offline — which would also prevent you from pushing a correction.

To guard against this, a device can fall back to a known-good network configuration that was established when the device was set up. If a platform-supplied configuration leaves the device unable to reach the platform, the device can revert to this baked-in configuration so it can be reached again.

You can control this behavior:

Setting Effect
Fallback enabled (default) If platform-supplied network configuration fails, the device reverts to its known-good configuration.
Fallback disabled The device always uses the platform-supplied configuration and never reverts.

A device can have more than one uplink — for example wired Ethernet plus cellular, or wired plus Wi-Fi. When multiple uplinks are configured, the device prefers the primary uplink and uses the others as backups, switching to a working uplink when the preferred one is unavailable.

A common, robust pattern is:

  1. Wired Ethernet as the primary uplink (DHCP).
  2. Wi-Fi or cellular as a backup that takes over when the wired link is down.

Cellular is especially useful as a last-resort uplink because it does not depend on local site infrastructure. Associate a SIM with the device during hardware registration, configure the cellular connection in your network YAML, and the device can fall back to it to stay manageable.

Proxy fallback

When a device is configured to reach the platform through a proxy, it still needs to stay reachable if that proxy becomes unavailable. The device evaluates the available paths to the platform and uses a working one, so a single failed proxy does not necessarily cut the device off from management.

This means you can introduce a proxy for normal operation without making it a single point of failure for device management, provided a viable path to the platform remains.

Putting it together

For a remote, hard-to-reach device, a resilient setup combines all three:

  • Keep network configuration fallback enabled so a bad push self-corrects.
  • Provide a backup uplink (cellular is ideal) so a single link failure does not isolate the device.
  • If you use a proxy, ensure a viable path to the platform remains so proxy problems do not block management.

Next steps

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Proxy configuration

If your devices reach the internet through a forward proxy, configure the proxy so that both the device’s connection to the SPEKTRA Edge platform and your workloads’ traffic are routed correctly.

What you can set

Proxy configuration consists of the standard proxy settings:

Setting Meaning
http_proxy Proxy URL for plain HTTP traffic.
https_proxy Proxy URL for HTTPS traffic.
no_proxy Hosts and networks that should bypass the proxy (comma-separated).

In addition, you can specify which network interfaces the device should use to reach the platform through the proxy, so control-plane traffic uses the intended path.

Where to set it

You can configure the proxy:

  • at image creation, so devices use the proxy from first boot, or
  • from the dashboard for a device that is already online.

The proxy applies both to the device’s own communication with the platform and to container workloads running on the device.

Fallback behavior

The device determines the best route to the platform and will fall back to a direct connection when the proxy is not usable, so a proxy outage does not necessarily take a device offline. If you require that all traffic traverse the proxy, ensure direct egress is blocked at the network level rather than relying on device configuration.

no_proxy recommendations

Add to no_proxy any destinations that must not go through the proxy, such as:

  • on-site services the device talks to directly (local registries, local APIs)
  • link-local and private ranges used on the device’s LAN

Next steps

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Connectivity & ports

This page lists what a device needs to reach on the network and what it accepts on its own interfaces, so you can plan firewall rules for the sites where your devices run.

Outbound connectivity (required)

A device reaches the SPEKTRA Edge platform over secure, outbound connections. Devices do not need any inbound connections from the platform — all communication is initiated by the device.

Destination Port Purpose
SPEKTRA Edge platform endpoints TCP 443 Provisioning, configuration, telemetry, log forwarding, and remote access — all over TLS.
Time sources UDP 123 Network time synchronization. See Time synchronization.
Public STUN servers UDP External IP address discovery.

At minimum, allow outbound TCP 443 to the platform and outbound UDP 123 to your time sources. If you use a proxy, the device’s platform traffic egresses through it.

Inbound (on the device)

By default a device exposes only what is needed to administer it locally:

Port Purpose
TCP 22 SSH access. Can be restricted or disabled — see SSH access.

The device also responds to local network discovery (mDNS) so it can be found by name on the local segment; this can be turned off with the device discovery setting.

Any ports your workloads expose are determined by the workloads you deploy, not by the OS.

Remote access does not require inbound ports

Operator actions such as opening a remote shell, transferring files, or streaming logs are carried over the device’s existing outbound connection to the platform. You do not need to open inbound ports to use them. See Remote access.

Firewall planning checklist

  • Allow outbound TCP 443 to the SPEKTRA Edge platform (directly or via proxy).
  • Allow outbound UDP 123 to your NTP sources.
  • Allow outbound UDP to your chosen STUN servers (or accept that external IP discovery is unavailable).
  • Decide whether local TCP 22 (SSH) should be reachable on your LAN.
  • Open any ports your workloads require, per workload.

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Time synchronization

Accurate time is important for secure connections, certificate validation, log correlation, and device attestation. Devices keep their clocks synchronized over the network using NTP.

Default behavior

Out of the box, a device synchronizes against public time sources, so a device with internet access keeps accurate time without any configuration.

Setting custom NTP servers

If your environment requires specific time sources — for example, internal NTP servers on an isolated network — you can provide your own NTP configuration. You can set it:

  • at image creation, so it applies from first boot, or
  • by placing an NTP configuration on the device’s configuration storage.

When custom NTP settings are provided, they take effect early in the boot process so the device’s clock is correct before it contacts the platform.

Recommendations

  • On networks without internet access, always configure reachable internal NTP servers; otherwise the device cannot correct its clock, which can cause secure connections and attestation to fail.
  • Make sure outbound UDP 123 to your time sources is allowed — see Connectivity & ports.