CLI Reference Guide-R04

Chapter 21 | ERPS Commands
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propagate-tc This command enables propagation of topology change messages for a secondary
ring to the primary ring. Use the no form to disable this feature.
Syntax
[no] propagate-tc
Default Setting
Disabled
Command Mode
ERPS Instance Configuration
Command Usage
◆ When a secondary ring detects a topology change, it can pass a message about
this event to the major ring. When the major ring receives this kind of message
from a secondary ring, it can clear the MAC addresses on its ring ports to help
the secondary ring restore its connections more quickly through protection
switching.
◆ When the MAC addresses are cleared, data traffic may flood onto the major
ring. The data traffic will become stable after the MAC addresses are learned
again. The major ring will not be broken, but the bandwidth of data traffic on
the major ring may suffer for a short period of time due to this flooding
behavior.
Example
Console(config-erps-inst)#propagate-tc
Console(config-erps-inst)#
bpdu-tcn-notify This command configures an ERPS instance to send BPDU TCN notifications. Use
the no form of this command to disable BPDU TCN notifications.
Syntax
[no] bpdu-tcn-notify
Default Setting
Disabled
Command Mode
ERPS Instance Configuration
Command Usage
When enabled, Spanning Tree topology change notification (TCN) BPDUs are
transmitted when an ERPS forwarding database (FDB) flush occurs on a ring
instance.