MSTP INTEROPERABILITY OF THE DELL™ POWERCONNECT™ 6200 SERIES SWITCHES WITH CISCO IOS AND CISCO
Figure 7: Multiple MSTP Regions
In Figure 8, a third region has been added to the topology. Even though this new region only consists of one bridge and has an MST Configuration Identifier that matches the bridges in Region 1, it will still be isolated into a region by itself. This is due to the fact that the only connection between Region 1 and Region 3 is through a different region.
The path of a frame for VLAN 20 can be traced through the MST active topology. A frame originating on an end station on bridge BrA in Region 1 will traverse the MSTI 2 active topology since its VID has been allocated to that instance. In looking for a destination match with a device in Region 3, it will pass through the boundary port in bridge BrC and continue through Region 2 using the instance MSTI 1. Assuming that port Pt2 on both bridge BrA2 and BrB2 are forwarding for the MSTI 1, the frame would arrive at the boundary port on bridge BrB2 and then be sent to Region 3. Upon arriving in Region 3, the frame would traverse MSTI 2 to the destination device.
APRIL 2008 | 24 |
