Figure 39. Normal Operating FRRP Topology
A virtual LAN (VLAN) is configured on all node ports in the ring. All ring ports must be members of the
Member VLAN and the Control VLAN.
The Member VLAN is the VLAN used to transmit data as described earlier.
The Control VLAN is used to perform the health checks on the ring. The Control VLAN can always pass
through all ports in the ring, including the secondary port of the Master node.
Ring Status
The ring failure notification and the ring status checks provide two ways to ensure the ring remains up
and active in the event of a switch or port failure.

Ring Checking

At specified intervals, the Master node sends a ring health frame (RHF) through the ring. If the ring is
complete, the frame is received on its secondary port and the Master node resets its fail-period timer and
continues normal operation.
If the Master node does not receive the RHF before the fail-period timer expires (a configurable timer),
the Master node moves from the Normal state to the Ring-Fault state and unblocks its Secondary port.
The Master node also clears its forwarding table and sends a control frame to all other nodes, instructing
them to also clear their forwarding tables. Immediately after clearing its forwarding table, each node
starts learning the new topology.
Force10 Resilient Ring Protocol (FRRP) 371