How Rrpp Works - H3C S3610 Series Operation Manual

Operation Manual – RRPP
H3C S3610&S5510 Series Ethernet Switches
There are two or more domains in a network, and there two different common nodes
between any two domains.
one and only one RRPP primary ring. In the case of multi-domain intersection, the rings
in different domains are independently configured. Each single domain can contain
multiple rings, among which there must be one and only one primary ring. The data
VLAN in one domain must be isolated from the data VLAN in another.

1.1.4 How RRPP Works

I. Polling mechanism
The primary port of the master node sends Health packets across the control VLAN
periodically.
If the ring works properly, the secondary port of the master node will receive
Health packets and the master node will maintain it in block state.
If the ring is torn down, the secondary port of the master node will not receive
Health packets after the timeout timer expires. The master node will release the
secondary port from blocking data VLAN while sending Common-Flush-FDB
packets to notify all transit nodes to update their own MAC entries and ARP
entries.
II. 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 port 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 VLAN while sending Common-Flush-FDB packet to
notify all the transit nodes, the edge nodes and the assistant nodes to update their own
MAC entries and ARP entries.
III. Ring recovery
The master node may find the ring is restored after a period of time after the ports
belonging to the RRPP domain on the transit node, the edge node or the assistant edge
node are up again. A temporary loop may arise in the data VLAN in this period. As a
result, broadcast storm occurs.
To prevent temporary loops, non-master nodes block them immediately (and permits
only the packets of the control VLAN) when they find their ports accessing the ring are
up again. The blocked ports are activated only when the nodes ensure that no loop will
be brought forth by these ports.
IV. Broadcast storm suppression mechanism in a multi-homed subring in
case of primary ring link failure
As shown in
When two links of the primary ring between the edge node and the assistant edge node
Figure 1-6
Figure 1-5, Ring 1 is the primary ring, and Ring 2 and Ring 3 are subrings.
defines three RRPP domains, each containing
1-8
Chapter 1 RRPP Configuration