On MCT ICL link fail, Loose-Loose mode is activated. MCT peers continue with their existing MCT KA and MDT join Primary/Secondary states and only the Primary MDT node receives the MDT traffic. This results in the MDT traffic to be forwarded to CCEP clients based on Local-Biased forwarding. The CEP ports on Secondary MDT node do not receive the traffic.
MCT peer node with KA role as Secondary, shuts down its CCEP interfaces and the LVTEP loopback interface. The spine nodes that join the Secondary MCT node initially, re-direct the PIM-SSM joins to the Primary MCT node. All CCEP MDT traffic egress out into the EVPN Fabric from the Primary MCT node. The traffic from the CEP port on Secondary MCT node cannot egress out into the EVPN Fabric and is dropped.