Switched UNI

Switched User Network Interface (S-UNI) allows the association of local endpoints to I-SIDs based on local port and VLAN together. With Switched UNI, the same VLAN can be used on one port to create an endpoint to one I-SID, and on another port to create an endpoint to another I-SID.

Switched UNI summary:
  • Switched UNI is a VLAN and ports associated with I-SIDs.

  • Local significance on the ports.

  • You can re-use the same VLAN to associate different ports with different I-SIDs.

  • You can use a different VLAN to the same ports, or you can assign different ports to the same I-SID.

  • Supports VLAN mapping on the local switch.

  • To accept untagged traffic, the port needs to be configured as untagged-traffic in the I-SID.

Use Switched UNI when either of the following apply:
  • Vlan ID (VID) reuse is required. The same VID is used on different broadcast domains (multi-tenant applications).

  • Multiple VLANs must be part of the same broadcast domain.

  • VID translation is required.

An example of an application for Switched UNI is a typical host and provider deployment, with a port and VID-based classification.

Switched UNI based MAC learning

MAC learning is done on I-SID MAC. When a packet ingresses on a port or MLT which is associated with Switched UNI I-SID, the system performs MAC look up based on the I-SID. Switched UNI operates on Any-To-Any  (ELAN) mode, there can be one or more ports associated to a Switched UNI I-SID. A packet that ingresses to a Switched UNI port on a BEB can transfer through the SPBM cloud, or can egress out another Switched UNI port configured to the same I-SID.

When a packet ingresses an NNI port, before egressing a Switched UNI port, the system performs a MAC Destination Address (DA) lookup based on the I-SID. If the DA lookup fails, the packet floods to all Switched UNI ports in the I-SID.

Considerations

Consider the following when you configure a Switched UNI:
  • The VLAN tag is removed before the traffic egresses out on the untagged-traffic port or MLT.

  • VLAN priority received on the packet is maintained across VLAN IDs.

  • Spanning tree is disabled on all Switched UNI ports, and the ports remain in forwarding state.

  • The Switched UNI I-SID is advertised to the SPBM cloud.

  • The Broadcast and unknown Unicast packets are flooded to all ports in the I-SID.

Limitations

  • You cannot change from one UNI type to another dynamically. The I-SID has to be deleted and created with new UNI type (Customer VLAN (C-VLAN), Transparent port user-network-interface (T-UNI), ELAN).

  • I-SID cannot be used by IPVPN, MVPN, SPBM dynamic multicast range, or Transparent Port UNI.

  • If the port is a member of MLT, the entire MLT has to be added to the VID.

  • The port is always in the forwarding state.

  • The same VID, port, or MLT cannot be member of more than one I-SID.

  • Static MAC, Static ARP and static IGMP group are not supported on Switched UNI enabled ports.

  • For a Switched UNI endpoint without a platform VLAN on the VSP 7400 Series, when MAC-in-MAC terminated traffic is sent out to the UNI endpoint the packet is re-marked based on existing QoS rules.

  • On VSP 8600 Series, dynamically learned Fabric Attach announced VLAN-ISID bindings and manually configured Switched-UNI end-points are not supported on the same interface.

BPDU handling on S-UNI port/MLT

The switch handles Bridge Protocol Data Units (BPDUs) according to whether or not you configure a platform VLAN.