Cisco 15327 - Manual (Page 281)

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Ethernet Card Software Feature and Configuration Guide, R7.2
Chapter 17 Configuring Cisco Proprietary Resilient Packet Ring
LFP Sequence
Figure 17-13 Cisco Proprietary RPR Link Fault Propagation Example
LFP Sequence
LFP updates are done through a Cisco discovery packet (CDP) packet extension. The update is sent
periodically and immediately after the master interface goes into a link-down state. LFP updates are sent
separately from normal CDPs, and the two types do not interact. Configuring or disabling CDP on the
interface has no effect on LFP updates.
When the master interface goes down, including an administrative shutdown, the slave interface is forced
down. When the master interface goes up, the slave interface goes back up. Administrative shutdown on
a slave interface will suspend the LFP function on that interface, and removing the shutdown will
reactivate LFP.
A link-down fault is also forced onto the slave link if the connection from the master to the slave fails.
Any of the following can cause a loss of connection:
• Removing or resetting the master ML-Series card.
• Shutdown or failure on both of the Cisco proprietary RPR paths between master and slave.
ML-Series RPR
ML-Series Card Master Interface
Original Link-fault
Hub Router
Propagated Link-faults
Access Switches and Routers
ML-Series Card Slave Interface
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