Each node on the ring connects through two ring ports. One port must be configured as the primary port; the other must be configured as the secondary port. The primary and secondary ports have significance only on a master node. The health-check messages are sent out the primary port of the master node, and the master node blocks the protected VLANs on the secondary port. The master node’s secondary EAPS port cannot be configured on ports that are already configured as follows: • Shared-port • MLAG ISC port There is no distinction between the primary and secondary ports on a transit node.