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 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.
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.
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.
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.
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.
The switch handles Bridge Protocol Data Units (BPDUs) according to whether or not you configure a platform VLAN.
When you configure a platform VLAN:
BPDUs are forwarded to the CPU by default.
For both the ingress and egress ports, BPDUs are not flooded in the S-UNI I-SID associated with the platform VLAN.
Note
If the platform VLAN is configured for the S-UNI port, you cannot enable BDPU forwarding.
When you DO NOT configure a platform VLAN:
BPDUs received on untagged-traffic ports are dropped by default.
To flood BPDUs in its I-SID, enable BPDU forwarding under S-UNI I-SID using the command untagged-traffic port <port no> bpdu enable.