Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) - Manual (Page 419)

Brocade 6910 Ethernet Access Switch Configuration Guide 363
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ERPS Commands
Command Mode
ERPS Configuration
Command Usage
• The RPL owner node detects a failed link when it receives R-APS (SF - signal fault) messages
from nodes adjacent to the failed link. The owner then enters protection state by unblocking
the RPL. However, using this standard recovery procedure may cause a non-EPRS device to
become isolated when the ERPS device adjacent to it detects a continuity check message
(CCM) loss event and blocks the link between the non-ERPS device and ERPS device.
CCMs are propagated by the Connectivity Fault Management (CFM) protocol as described
under
“CFM Commands” on page 517. If the standard recovery procedure were used as shown
in the following figure, and node E detected CCM loss, it would send an R-APS (SF) message to
the RPL owner and block the link to node D, isolating that non-ERPS device.
When non-ERPS device protection is enabled on the ring, the ring ports on the RPL owner node
and non-owner nodes will not be blocked when signal loss is detected by CCM loss events.
• When non-ERPS device protection is enabled on an RPL owner node, it will send non-standard
health-check packets to poll the ring health when it enters the protection state. It does not use
the normal procedure of waiting to receive an R-APS (NR - no request) message from nodes
adjacent to the recovered link. Instead, it waits to see if the non-standard health-check packets
loop back. If they do, indicating that the fault has been resolved, the RPL will be blocked.
After blocking the RPL, the owner node will still transmit an R-APS (NR, RB - ring blocked)
message. ERPS-compliant nodes receiving this message flush their forwarding database and
unblock previously blocked ports. The ring is now returned to Idle state.
Example
Console(config-erps)#non-erps-dev-protect
Console(config-erps)#
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 Configuration
non-ERPS
A
non-ERPS
RPL
Owner
RPL
X X
blocked blocked
fault
B C D E F