Related Documentation
Understanding Layer 2 Virtual Switches Instances
At Layer 2, you can group one or more VLANs into a single routing instance to form a virtual switch instance. A virtual switch instance is composed of VLANs. The virtual switch instance isolates a LAN segment and contains most Layer 2 functions, such as spanning-tree protocol instances and VLAN ID spaces, into it’s own smaller, logical network. Splitting Layer 2 traffic using virtual switch instances allows you to more logically organize your Layer 2 traffic into multiple “virtual” Layer 2 networks.
A default virtual switch, called default-switch, is automatically created when a virtual switch is configured. All Layer 2 traffic not assigned to a VLAN in a virtual switch automatically becomes part of the default virtual switch.
You can configure a virtual switch to participate only in Layer 2 bridging and optionally to perform Layer 3 routing. In addition, you can configure spanning-tree protocols (STPs) within the virtual switch to prevent forwarding loops. For more information about how to configure Layer 2 logical ports on an interface, see the Junos® OS Network Interfaces.
You can associate one or more logical interfaces configured as trunk interfaces with a virtual switch. A trunk interface, or Layer 2 trunk port, enables you to configure a logical interface to represent multiple VLANs on the physical interface. For more information about how to configure trunk interfaces, see the Junos® OS Network Interfaces.
You can also configure Layer 2 forwarding and learning properties for the virtual switch.
