Cisco Systems 15327 Configuring a Span Shutdown, Configuring Keepalive Events

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Ethernet Card Software Feature and Configuration Guide, R7.2
January 2009
Chapter 26 Configuring IEEE 802.17b Resilient Packet Ring
Configuring a Span Shutdown
Configuring a Span Shutdown
The rpr-ieee shutdown command performs the same task as the rpr-ieee protection request
forced-switch command.
To cause a forced switch on the span of the interface, perform the following procedure, beginning in
global configuration mode:
Configuring Keepalive Events
A station receives fairness messages from a link to determine its status. When the number of
milliseconds that pass without receiving a fairness message from the neighboring stations exceeds a
specified timer, a keepalive event is triggered. The keepalive event generates a protection event.
The timer can have a different value on each span and must be greater than or equal to the hold-off timer.
This feature is independent of the fairness algorithm itself, but is still a function performed by the
fairness machine.
The RPR protection switch can be delayed by changing the Hold-off timer and the RPR keepalive-timer.
These should be configured according to the type of circuit
• If the TDM circuit is unprotected, then both these timers should be left at their default values. No
extra configuration is required in this case.
• When the TDM circuit is protected (e.g., path protection or BLSR) , the RPR protection switch
should be delayed till the protection-switch at the TDM level has finished.
– For example : If it takes 60ms for the TDM protection switch to complete. Then both the hold
off timer and the RPR keepalive timer must be configured higher than 60 milliseconds. If either
of these timers is left at its default value, then it will trigger the RPR protection before TDM
protection is over.
Caution If TDM protection is configured along with RPR, and if the RPR protection switch kicks in before the
TDM protection switch over is complete, the system behavior is unpredictable/unstable.
Command Purpose
Step 1 Router(config)# interface rpr-ieee 0 Activates interface configuration mode to
configure the RPR-IEEE interface.
Step 2 Router(config-if)# rpr-ieee shutdown {east
| west}
Causes a forced switch on a specified span of the
interface.
Step 3 Router(config)# end Returns to privileged EXEC mode.
Step 4 Router# copy running-config startup-config (Optional) Saves configuration changes to the
TCC2/TCC2P flash database.