H3C S5120-EI Series - RRPP Timers; How RRPP Works

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Common-Flush-FDB
The master node initiates Common-Flush-FDB packets to instruct the transit nodes
to update their own MAC entries and ARP/ND entries when an RRPP ring transits
to Disconnect state. FDB stands for Forwarding Database.
Complete-Flush-FDB
The master node initiates Complete-Flush-FDB packets to instruct the transit nodes
to update their own MAC entries and ARP/ND entries and release blocked ports
from being blocked temporarily when an RRPP ring transits to Health state.
Edge-Hello
The edge node initiates Edge-Hello packets to examine the SRPTs between the
edge node and the assistant-edge node.
Major-Fault
The assistant-edge node initiates Major-Fault packets to notify the edge node of
SRPT failure when an SRPT between edge node and assistant-edge node is torn
down.
NOTE:
RRPPDUs of subrings are transmitted as data packets in the primary ring, and RRPPDUs of the primary
ring can only be transmitted within the primary ring.
RRPP timers
When RRPP checks the link state of an Ethernet ring, the master node sends Hello packets out of the
primary port according to the Hello timer and determines whether its secondary port receives the Hello
packets based on the Fail timer.
• The Hello timer specifies the interval at which the master node sends Hello packets out of the
primary port.
• The Fail timer specifies the maximum delay between the master node sending Hello packets out of
the primary port and the secondary port receiving the Hello packets from the primary port. If the
secondary port receives the Hello packets sent by the local master node before the Fail timer expires,
the overall ring is in Health state. Otherwise, the ring transits into the Disconnect state.
NOTE:
In an RRPP domain, a transit node learns the Hello timer value and the Fail timer value on the master node
through the received Hello packets, ensuring that all nodes in the ring network are consistent in the two
timer settings.
How RRPP works
Polling mechanism
The polling mechanism is used by the master node of an RRPP ring to check the Health state of the ring
network.
The master node periodically sends Hello packets out of its primary port, and these Hello packets travel
through each transit node on the ring in turn:
• If the ring is complete, the secondary port of the master node will receive Hello packets before the
Fail timer expires and the master node will keep the secondary port blocked.
• If the ring is torn down, the secondary port of the master node will fail to receive Hello packets
before the Fail timer expires. The master node will release the secondary port from blocking data