3Com Switch 7754, Configuration Manual

Page: 904 / 940

904 C
HAPTER
82: RRPP C
ONFIGURATION
Ethernet ring
An Ethernet ring is a ring-shaped Ethernet topology, on which a RRPP domain is
based. An RRPP domain consists of a primary ring and one or more subrings. In
configuration, the level of the primary ring is level 0, and that of the subrings is
level 1.
As shown in Figure 250, RRPP domain 1 consists of ring 1 and ring 2. If their levels
are set to level 0 and level 1 respectively, ring 1 is the primary ring and ring 2 is the
subring.
Each ring is in one of the following two states:
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Healthy state: The physical links of the ring network are connected.
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Broken state: A certain physical link is disconnected on the ring network.
Control VLAN and data VLAN
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A control VLAN is a special VLAN used to transfer RRPP packets. The port on
each switch for connecting the switch with the Ethernet ring belongs to the
control VLAN, and only the ports connected to the Ethernet ring can be added
to the control VLAN. It is not allowed to configure an IP address for the
interface of the control VLAN. You can configure the control VLAN of the
primary ring. The control VLAN of the subring is assigned by the system
automatically. The ID of the subring control VLAN is the ID of the primary ring
control VLAN plus 1.
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A data VLAN is used to transfer data packets. A data VLAN contains the ports
connecting the switch with the Ethernet ring network and other ports.
Node
Every switch on an Ethernet ring network is a node. Node roles are as follows:
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Master node: The node that initiates loop detection and prevents data loops
prevention is the master node. Each ring has one and only one master node.
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Transit node: All nodes other than the master node on a ring are transit nodes.
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Edge node: An edge node is located on the primary ring and a subring at the
same time. An edge node serves as a transit node on the primary ring and an
edge node on a subring. In an RRPP domain, there are two edge nodes on a
subring. You must specify any one of them as assistant edge node so far the
configuration can tell the difference between the edge node and assistant
edge node.
The node roles are determined by user configuration. As shown in Figure 250,
Switch A is the master node on ring 1, and Switch B, Switch C and Switch D are
transit nodes on ring 1. Switch B and Switch C are edge nodes because they are
both on ring 2. You can specify one of them as edge node, and the other as
assistant edge node.
Primary port and secondary port
The master node and each of the transit nodes are connected to an Ethernet ring
through two ports, of which one is the primary port and the other is the secondary
port. The node roles are determined by user configuration.
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The primary port and secondary port of the master node