Deploying Parallel Redundancy Protocol within a Converged Plantwide Ethernet Architecture CVD

Device Manager

Stratix RedBox IES provides information about connected VDANs on the Device Manager Monitor->Status ->PRP page. The VDAN MAC addresses are learned automatically from the switch MAC table. The RedBox IES sends PRP supervisory frames for each VDAN via the PRP channel ports.

Figure 4-1 VDAN Table

RedBox IES learns about DANs and SANs in the network from the supervisory frames received on the PRP channel ports. These frames are propagated within a VLAN as special Layer 2 multicast frames.

The DAN and SAN information can be viewed on the Monitor->Status->PRP page.

Figure 4-2 Node Table

• Time To Live (TTL) value shows the number of seconds since the last received frame. Node entries age out and are removed from the tables after 60 seconds.
• The switch supports a maximum of 512 SAN and DAN entries in the Node table. If the Node table is full, the switch treats new nodes as a DAN by default.
• The switch supports a maximum of 512 VDAN entries in the VDAN table. If the VDAN table is full, the switch cannot send supervisory frames for new VDANs.
• In a multi-VLAN network with PRP channel ports in the trunk mode, the RedBox IES receives supervisory frames and displays information about nodes in all VLANs enabled on the trunk
• The number of DAN packets received from LAN A and LAN B should be the same or very close in a normally functioning network. The increasing difference may be due to dropping packets in one of the LANs and may require further troubleshooting.
• There should be no Wrong Packets entries. If any exist and are increasing, this indicates incorrect cabling of a DAN or a RedBox.

Note DANs, SANs, and VDANs can be manually added to and deleted from the corresponding tables on the Configure->PRP page. Normally dynamic learning should be sufficient. Static configuration may be needed only if PRP devices do not support supervisory frames.

Command Line Interface

CLI diagnostics commands for PRP provide more detailed information for troubleshooting.

• show prp statistics egress command shows detailed packet counts and byte counts for transmitted frames over the PRP channel.

• show prp statistics ingress command shows detailed packet counts and byte counts for different types of frames received on the PRP channel.

• Ingress Warning status indicates following conditions for LAN A or LAN B:

– Loss of communication for three seconds on one LAN, but not the other. This condition applies to traffic from all nodes. The condition is cleared once communication is restored for three seconds.

– Node status is active on one LAN but not the other. This means that no packets were received from one of the PRP nodes in the switch table (DANs or VDANs) on one of the LANs for three seconds. The condition is cleared once packets are received again within three seconds.

– Packets from a wrong LAN were received on one of the ports in the past second. The condition is cleared once no wrong packets are received for one second.

– Warning counts and wrong LAN counts show total number of faults since the last reset of counters.

• show prp statistics ptp command displays PTP traffic counters for the PRP channel (which is sent and received independently on each port, bypassing PRP duplication mechanism).

• clear prp statistics command resets all PRP counters and could be useful when troubleshooting an ongoing problem with PRP communication.

• show prp node-table statistics command provide warning status and received count per LAN for each PRP node learned by the RedBox, including DANs, SANs, remote VDANs, and other RedBoxes.

Figure 4-3 Node Table Statistics