HP A5120 EI Configuration Manual page 61

As shown in
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.
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 port's role.
Primary port and secondary ports of a master node have the following functions:
1.
The primary port sends loop-detect packets; the secondary port receives loop-detect packets.

When an RRPP ring is in Health state, the secondary port of the master node logically denies data

VLANs and permits only the packets of the control VLANs.
When an RRPP ring is in Disconnect state, the secondary port of the master node permits data

VLANs—forwards packets of data VLANs.
There is no difference in function between the primary port and the secondary port of a transit
2.
node. Both transfer protocol packets and data packets over an RRPP ring.
As shown in
node on Ring 1, and its Port 2 is the secondary port of the master node on Ring 1. Device B, Device C,
and Device D are the transit nodes of Ring 1. Their Port 1s are primary ports of transit nodes on Ring 1,
and their Port 2s are secondary ports of transit nodes on Ring 1.
Common port and edge port
Common ports: Edge node ports and assistant-edge node ports that connect to the primary ring are
common ports.
Edge ports: Edge node ports and assistant-edge node port s that connect only to the subrings are edge
ports.
As shown in
and Device C's Port 1 and Port 2 access the primary ring, so they are common ports. Device B's Port 3
and Device C's Port 3 access only the subring, so they are edge ports.
RRPP ring group
To reduce Edge-Hello traffic, you can configure a group of subrings on the edge node or assistant-edge
node. (For more information about Edge-Hello packets, see "RRPPDUs.") Such rings have the following
requirements:
You must configure a device as the edge node of these subrings.

You must configure a different device as the assistant-edge node of these subrings.

The subrings of the edge node and assistant-edge node must connect to the same subring packet

tunnels (SRPTs) in the major ring so that Edge-Hello packets of the edge node of these subrings travel
to the assistant-edge node of these subrings over the same link.
An RRPP ring group configured on the edge node is an edge node RRPP ring group. An RRPP ring group
configured on an assistant-edge node is an assistant-edge node RRPP ring group. Up to one subring in an
edge node RRPP ring group is allowed to send Edge-Hello packets.
Figure 13, Ring 1 is the primary ring and Ring 2 is a subring. Device A is the master node of
Figure 13, Device A is the master node of Ring 1. Its Port 1 is the primary port of the master
Figure 13, Device B and Device C lie on Ring 1 and Ring 2. Device B's Port 1 and Port 2
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