Skip Navigation Links
Exit Print View
| Sun Ethernet Fabric Operating System ### STP Administration Guide

Search Scope:

- This Document
- Entire Library

#### Operations in an MST Region

All bridges in a single MST region have the same regional configuration. The communication among bridges inside the MST region is through the IST. The communication across bridges is taken care of by the CIST (common internal spanning tree that spans across the entire topology irrespective of MST and SST regions). All bridge ports are part of all instances available in the system. Thus, when the MSTP protocol operates, the port role and port state are calculated for the CIST (common spanning tree context) and separately for each instance. The operation of the protocol arrives at a single common/active topology consisting of all the bridges in the topology, which is the CIST. The bridge with the best bridge ID is chosen as the CIST root. Apart from the CIST root, the regions also calculate MSTI regional roots for each of the MST instances active inside the region and a CIST regional root towards the CIST root. The port on the CIST regional root towards the CIST root is selected as the master port.

Copyright © 2010, 2012, Oracle and/or its affiliates. All rights reserved. Legal Notices |