Glossary · Industrial communication
Unmanaged switch
Also known as: Plug-and-play switch, Unmanaged Ethernet switch
German: Unmanaged Switch
In networking, an unmanaged switch is an Ethernet switch that forwards frames automatically without any configuration interface, so it offers no VLANs, no traffic prioritization settings, no redundancy protocols and no remote diagnostics.
- Industrial communication
In one sentence
An unmanaged switch forwards Ethernet frames without configuration, but offers no VLANs, prioritization settings or diagnostics.
Example
A small stand-alone machine uses an unmanaged switch in its cabinet to connect the PLC, the HMI and a service port.
How it applies
- Engineering: Unmanaged switches are acceptable in small, isolated machine networks with little traffic. They pass all traffic, including broadcast and multicast, to all ports, which can overload devices in networks with multicast-heavy protocols.
- Security: Without configuration there is no segmentation, no port security and no logging. Anyone who plugs into a free port is in the network.
- Diagnostics: Faults can only be seen on the LEDs; there is no remote status reporting.
- Documentation: The documentation team documents where unmanaged switches are used and why, and states whether the product's network requirements (for example real-time protocols, conformance classes) permit them. Some real-time protocols specify switch requirements that unmanaged switches may not meet.
Unmanaged switch vs. managed switch
A Managed switch can be configured, monitored and secured. An unmanaged switch is simpler and cheaper but gives up control and visibility.