Request for Interpretation of whether or not a loss of link causes a spanning tree topology change.
The text of IEEE Std 802.1D:1998 does not explicitly couple the operational state of a MAC to the Disabled Port state; however, the intent of the standard is that detectable failure of a MAC should cause the Bridge Port supported by that MAC to enter the Disabled state, as indicated by the last paragraph of 8.3.5 and the explanation of the port state transitions of type (2) shown in Figure 8-3. A transition to the Disabled Port state causes the Bridge to initiate a topology change notification, unless, for the Port concerned, topology change detection has been explicitly disabled (8.5.5.10). Current technical and editorial corrections to this standard, proposed under project P802.1t, include a macEnabled and a macOperational parameter in the Internal Sublayer Service definition. The macEnabled parameter allows administrative control over the availability of a MAC; the macOperational parameter reflects the operational state of a MAC, and is set to FALSE if the MAC detects a link failure, or if macEnabled is FALSE. The definition of the Disabled Port state is extended to explicitly state that the Disabled state is entered if macOperational becomes FALSE.
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