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RRPP ring
A ring-shaped Ethernet topology is called an "RRPP ring". RRPP rings fall into two types: primary ring and
subring. You can configure a ring as either the primary ring or a subring by specifying its ring level. The
primary ring is of level 0, and a subring is of level 1. An RRPP domain contains one or multiple RRPP rings,
one serving as the primary ring and the others serving as subrings. A ring can be in one of the following
states:
• Health state—All the physical links on the Ethernet ring are connected
• Disconnect state—Some physical links on the Ethernet ring are broken
As shown in Figure 11, Domain 1 con
tains two RRPP rings: Ring 1 and Ring 2. The level of Ring 1 is set
to 0, and that of Ring 2 is set to 1. Ring 1 is configured as the primary ring, and Ring 2 is configured as
a subring.
Control VLAN and data VLAN
1. Control VLAN
In an RRPP domain, a control VLAN is a VLAN dedicated to transferring Rapid Ring Protection
Protocol Data Units (RRPPDUs). On a device, the ports accessing an RRPP ring belong to the control
VLANs of the ring, and only such ports can join the control VLANs.
An RRPP domain is configured with two control VLANs: one primary control VLAN, which is the
control VLAN for the primary ring, and one secondary control VLAN, which is the control VLAN for
subrings. All subrings in the same RRPP domain share the same secondary control VLAN. After you
specify a VLAN as the primary control VLAN, the system automatically configures the VLAN whose
ID is the primary control VLAN ID plus one as the secondary control VLAN.
IP address configuration is prohibited on the control VLAN interfaces.
2. Data VLAN
A data VLAN is a VLAN dedicated to transferring data packets. Both RRPP ports and non-RRPP
ports can be assigned to a data VLAN.
Node
Each device on an RRPP ring is a node. The role of a node is configurable. RRPP has the following node
roles:
• Master node—Each ring has one and only one master node. The master node initiates the polling
mechanism and determines the operations to be performed after a change in topology.
• Transit node—Transit nodes include all the nodes except the master node on the primary ring and
all the nodes on subrings except the master nodes and the nodes where the primary ring intersects
with the subrings. A transit node monitors the state of its directly-connected RRPP links and notifies
the master node of the link state changes, if any. Based on the link state changes, the master node
decides the operations to be performed.
• Edge node—A special node residing on both the primary ring and a subring at the same time. An
edge node serves as a master node or a transit node on the primary ring and an edge node on the
subring.
• Assistant-edge node—A special node residing on both the primary ring and a subring at the same
time. An assistant-edge node serves as a master node or a transit node on the primary ring and an
assistant-edge node on the subring. This node works in conjunction with the edge node to detect the
integrity of the primary ring and to perform loop guard.
As shown in Figure 11, R
ing 1 is the primary ring and Ring 2 is a subring. Device A is the master node
of Ring 1, and Device B, Device C, and Device D are the transit nodes of Ring 1. Device E is the master
node of Ring 2, Device B is the edge node of Ring 2, and Device C is the assistant-edge node of Ring 2.
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