The use of multi-chassis ring control in a combination with the plain VPLS SAP is supported by the FDB in individual ring nodes, in case the link (or ring node) failure cannot be cleared on the 7750 SR or 7950 XRS.
This combination is not easily blocked in the CLI. If configured, the combination may be functional but the switchover times are proportional to MAC aging in individual ring nodes and, or to the relearning rate because of the downstream traffic.
Redundant plain VPLS access in ring configurations, therefore, exclude corresponding SAPs from the multi-chassis ring operation. Configurations such as M-VPLS can be applied.