3Com S7906E Configuration Manual page 2154

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 referred to as a node. The role of a node is configurable. There are 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 node residing on both the primary ring and a subring at the same time. An edge node
is a special transit node that serves as a transit node on the primary ring and an edge node on the
subring.
Assistant-edge node: A node residing on both the primary ring and a subring at the same time. An
assistant-edge node is a special transit node that serves as 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 perform loop guard.
As shown in Figure 1-1, Ring 1 is the primary ring and Ring 2 is a subring. Device A is the master node
of Ring 1, 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.
Primary port and secondary port
Each master node or transit node has two ports connected to an RRPP ring, one serving as the primary
port and the other serving as the secondary port. You can determine the role of a port.
1) In terms of functionality, the difference between the primary port and the secondary port of a
master node is:
The primary port and the secondary port are designed to play the role of sending and receiving
loop-detect packets respectively.
When an RRPP ring is in Health state, the secondary port of the master node will logically deny
data VLANs and permit only the packets of the control VLANs.
When an RRPP ring is in Disconnect state, the secondary port of the master node will permit data
VLANs, that is, forward packets of data VLANs.
2) In terms of functionality, there is no difference between the primary port and the secondary port of
a transit node. Both are designed for transferring protocol packets and data packets over an RRPP
ring.
As shown in Figure 1-1, Device A is the master node of Ring 1. Port 1 and Port 2 are the primary port
and the secondary port of the master node on Ring 1 respectively. Device B, Device C, and Device D
are the transit nodes of Ring 1. Their Port 1 and Port 2 are the primary port and the secondary port on
Ring 1 respectively.
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