Cisco proprietary rpr keep alive, Configuring cisco proprietary rpr keep alive – Cisco 15327 User Manual
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Ethernet Card Software Feature and Configuration Guide, R7.2
Chapter 17 Configuring Cisco Proprietary Resilient Packet Ring
Cisco Proprietary RPR Keep Alive
Example 17-6 Monitor and Verify LFP
Router# show link-fault
Link Fault Propagation Configuration:
-------------------------------------
LFP Config Mode : LFP_SLAVE
LFP Master State : LFP_STATUS_DOWN
Interfaces configured for LFP:
FastEthernet0 (down)
Cisco Proprietary RPR Keep Alive
The keep alive mechanism for Cisco proprietary RPR POS interfaces sends keep-alive packets onto SPR
links connecting adjacent nodes. This mechanism protects against failures undetected by the
SONET/SDH layer. Keep alive is off by default.
With this feature enabled, the Cisco proprietary RPR POS port wraps when it fails to receive three
consecutive keep-alives.When a link is down due to an interruption in keep-alive reception, it raises a
critical LINK-KEEPALIVE alarm on SONET/SDH. The Cisco proprietary RPR POS port unwraps and
the alarm clears only after receiving ten consecutive keep-alive packets. Keep alive failures are not
dependant on cyclic redundancy check (CRC) errors. Keep-alive is also supported on DRPRI for POS
interfaces. It is not supported on Gigabit EtherChannel (GEC).
Keep alive detection takes more than 50 ms. This time is added to the standard under 50 ms switching
time of SONET/SDH to result in a total recovery time of greater than 50 ms.
Configuring Cisco Proprietary RPR Keep Alive
Caution
When enabling the keep-alive feature on a Cisco proprietary RPR that is carrying traffic, it is highly
recommended that users first set the underlying POS circuit to OOS,DSBLD in SONET
or
Locked,disabled in SDH,
which will wrap the Cisco proprietary RPR in the standard sub-50 msec. You
can then enable the keep alive and put the circuit back to IS state in SONET or Unlocked in SDH. This
ensures that traffic experiences a sub-50 msec hit when Cisco proprietary RPR keep alives are enabled.
Note
The Cisco proprietary RPR keep alive requires the spr or multiprotocol label switching
(
mpls) working
microcode image for the ML-Series card.