Rrpp Timers; How Rrpp Works - HPE FlexNetwork HSR6800 series Configuration Manual

Type
Edge-Hello
Fast-Edge-Hello
Major-Fault

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 Disconnect
state.
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 sends Hello packets out of its primary port periodically, 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 VLANs and sending Common-Flush-FDB packets to instruct all transit nodes to update
their own MAC entries and ARP/ND entries.
Link down alarm mechanism
The transit node, the edge node or the assistant-edge node sends Link-Down packets to the master
node immediately when they find any of its own ports belonging to an RRPP domain is down. Upon
the receipt of a Link-Down packet, the master node releases the secondary port from blocking data
VLANs and sending Common-Flush-FDB packet to instruct all the transit nodes, the edge nodes and
the assistant-edge nodes to update their own MAC entries and ARP/ND entries. After each node
updates its own entries, traffic is switched to the normal link.
Ring recovery
The master node might find the ring is restored after a period of time after the ports belonging to the
RRPP domain on the transit nodes, the edge nodes, or the assistant-edge nodes are brought up
Description
The edge node initiates Edge-Hello packets to examine the SRPTs between the
edge node and the assistant-edge node.
The edge node initiates Fast-Edge-Hello packets to fast examine the SRPTs
between it and the assistant-edge node.
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.
73