Specifications

ALAXALA Ring Configuration Guide (Edition 1)

(3) When a node fault occurs in the Ring-STP node working as the root bridge

In this case, both the Ring Protocol and STP have a failure. Because the ring network detects the fault

earlier than STP does, the ring network performs a failure operation first, followed by a failure operation

by STP.

After STP changes the topology, the other Ring-STP node in the base sends flush frames into the ring

network.

Figure 2.4

-3 shows how the Ring Protocol and STP work if such a fault occurs.

Figure 2.4-3 Ring-STP node fault operation when the Ring Protocol and STP are used

1. A fault occurs in the Ring-STP node selected as the root bridge in base 2.

2. The ring detects the fault and switches the path in the ring.

3. STP configured in base 2 also detects the fault, changes the topology, and then clears the MAC address

tables in the base.

4. Because the node working as the root bridge for STP in base 2 has a fault, the other Ring-STP node sends

flush frames into the ring network to clear the MAC address tables of the nodes belonging to the ring

network in the other base (the nodes not in base 2 in the above figure).

5. The MAC address tables in all the nodes are updated, restoring communication.

2.4.3 Ring port restrictions when STP is also used

You cannot use the following STP functions on the ring ports of a device that uses Ring Protocol and STP

together:

- BPDU filtering functionality

- BPDU guard functionality

- Loop guard functionality

- Root guard functionality

- PortFast functionality

R: Ring node

S: STP node

RS: Ring-STP node

: Base

: Ring BLK port

: Ring FWD port

: STP BLK port

: STP FWD port

Base: 2

Base: 1

Root bridge

Flush

frames