Cisco 15327 - Manual (Page 282)

17-30
Ethernet Card Software Feature and Configuration Guide, R7.2
Chapter 17 Configuring Cisco Proprietary Resilient Packet Ring
Propagation Delays
• Disabling LFP on the master interface.
Link faults only propagate from master to slave. Normal slave link faults are not propagated.
Cisco proprietary RPR wrapping and unwrapping has no effect on LFP.
Propagation Delays
Propagation delay includes the carrier-delay time on the slave interface. The carrier-delay time is
configurable and has a default of 200 ms. See the
“Configuring Cisco Proprietary RPR” section on
page 17-7 for more information on configuring carrier-delay time.
Different propagation delays apply to different LFP scenarios:
• Propagation delay between master link-down and slave link-down is 50 ms plus the carrier-delay
time on the slave interface.
• Propagation delay between master link-up and slave link-up has an additional built-in delay at the
master interface to prevent interface flapping. Link-up propagation takes approximately 50 to
200 ms plus the carrier-delay time on the slave interface.
• Propagation delay from when the master-to-slave link fails until slave link-down occurs is
approximately 600 ms plus the carrier-delay time on the slave interface.
Configuring LFP
Figure 17-13 on page 17-29 illustrates an example of Cisco proprietary RPR configured with LFP. The
process of configuring LFP consists of the following tasks:
1. Configure one ML-Series card Gigabit Ethernet interface as a master link.
2. Configure the Gigabit Ethernet or Fast Ethernet interfaces for the other ML-Series cards as slave
links.
To enable and configure the LFP master link, perform the following procedure, beginning in global
configuration mode:
Command Purpose
Step 1 Router# interface gigabit ethernet number Activates interface configuration mode to
configure the Gigabit Ethernet interface.
Step 2 Router(config-if)# link-fault rpr-master Enables link-fault master status on the interface.
The no form of this command disables link-fault
master status.
Step 3 Router(config-if)# no shutdown Enables the interface by preventing it from
shutting down.
Step 4 Router(config)# end Returns to privileged EXEC mode.
Step 5 Router# copy running-config startup-config (Optional) Saves configuration changes to the
TCC2/TCC2P flash database.