MVID 26h - Report NAUN Change

Destination Address: C0-00-00-00-00-10 (LAN Manager)

Destination Class: 4 (Configuration Report Server)

Source Class: 0 (ring station)

Subvectors: SVID 0Bh - Physical Drop Number

This frame is used in the ring poll process to report a change in the stored upstream address (SUA; also referred to as NAUN) of the station that is upstream from the adapter generating the report NAUN change MAC frame. This frame is sent to the functional address of the network manager / configuration report server (CRS).

A NAUN change may have one of two reasons:

1. New upstream neighbor because the former NAUN stopped operation.

2. New upstream neighbor because of a new inserted station.

'Report NAUN change' is also referred to as 'report SUA change'.