Switch virtual interface

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A switch virtual interface (SVI) represents a logical layer-3 interface on a switch.

VLANs divide broadcast domains in a LAN environment. Whenever hosts in one VLAN need to communicate with hosts in another VLAN, the traffic must be routed between them. This is known as inter-VLAN routing. On layer-3 switches it is accomplished by the creation of layer-3 interfaces (SVIs). Inter VLAN routing, in other words routing between VLANs, can be achieved using SVIs. [1]

SVI or VLAN interface, is a virtual routed interface that connects a VLAN on the device to the Layer 3 router engine on the same device. Only one VLAN interface can be associated with a VLAN, but you need to configure a VLAN interface for a VLAN only when you want to route between VLANs or to provide IP host connectivity to the device through a virtual routing and forwarding (VRF) instance that is not the management VRF. When you enable VLAN interface creation, a switch creates a VLAN interface for the default VLAN (VLAN 1) to permit remote switch administration.

SVIs are generally configured for a VLAN for the following reasons:

SVIs advantages include:

An SVI can also be known as a Routed VLAN Interface (RVI) by some vendors. [2]

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References

  1. Hamza, Arif (14 September 2021). "Switch Virtual Interfaces". Cisco Education.
  2. "Understanding Routed VLAN Interfaces on EX Series Switches" . Retrieved 29 May 2013.