The system learns the MACs based on the I-SID to MAC binding. When a packet ingresses on a port, which is associated with Switched UNI (S-UNI) I-SID, the system performs MAC look up based on the I-SID. The RADIUS server provides the VLAN:I-SID assignment.
Important
If the default untagged S-UNI is used, you must have a platform VLAN associated with it. This is required to properly transmit traffic and to generate MAC learning events for traffic sent to MAC-based S-UNIs.When an untagged S-UNI is present on the port, the untagged MAC is initially learned on that S-UNI. When an untagged S-UNI does not exist on the port, the untagged MAC is learned on a special (internal) VLAN. The RADIUS server provides the VLAN:I-SID assignment.
MAC learning for tagged traffic occurs only if there is a tagged S-UNI with the corresponding C-VID on that port. The RADIUS server reconfirms the S-UNI that performed MAC learning.