switchid

Switchid is a term used to refer to the identifier that uniquely identifies a network switch within a management or control plane. It is employed by various protocols and management systems to distinguish one switch from another in a network, data center, or virtual environment. The specific format and method of assignment can vary by platform, vendor, and protocol, but the underlying purpose is the same: to provide a stable, unique reference to a particular switch.

In practice, switchid can take several forms. Commonly, it is a numeric value, sometimes represented in hexadecimal. In some environments, the switch identifier is derived from the switch’s hardware address, such as a MAC address, or it may be a locally assigned value that is guaranteed to be unique within the relevant management domain. In software-defined networking and OpenFlow deployments, the switch identifier is often called the datapath_id and is a 64-bit value used by controllers to address and manage the switch. In other contexts, identifiers may be advertised through link-layer discovery protocols (for example LLDP) or stored in network inventory systems.

Uses and contexts. OpenFlow controllers rely on the switchid/datapath_id to track and manage switches. Virtual switches, such as Open vSwitch, also use a datapath_id as their switch identifier. In network management and monitoring, the switchid helps correlate events, performance data, and configurations to the correct device. Some vendors allow manual configuration of the switchid, while others assign it automatically during provisioning.

Security and design considerations. Switchids must be globally unique within the management domain to avoid misconfiguration and misrouting of control traffic. Administrators should plan a scalable scheme, minimize changes to switchids after deployment, and ensure consistency across management tools.

See also: datapath_id, OpenFlow, LLDP, Open vSwitch, network management.