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Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
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Chapter 12 Configuring Resilient Ethernet Protocol
Configuring Resilient Ethernet Protocol (REP)

Configuring REP as Dual Edge No-Neighbor Port

For REP operation, you need to enable it on each segment interface and identify the segment ID.
Effective with Cisco IOS release 15.4.(1)S, you can configure the non-REP switch facing ports on a
single device as dual edge no-neighbor ports. These ports inherit all properties of edge ports, and
overcome the limitation of not converging quickly during a failure.
Figure 12-5 Dual Edge No-neighbor Topology
In access ring topologies, the neighboring switch might not support REP, as shown in Figure 12-5. In
this case, you can configure the non-REP facing ports (E1 and E2) as edge no-neighbor ports. These
ports inherit all properties of edge ports, and you can configure them the same as any edge port, including
configuring them to send STP or REP topology change notices to the aggregation switch. In this case the
STP topology change notice (TCN) that is sent is a multiple spanning-tree (MST) STP message.
Complete these steps to enable and configure REP as dual edge no-neighbor port:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. rep segment segment-id edge no-neighbor [primary | preferred]
REP not supported device
REP not supported device
REP No-Neighbour Ports
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E2
E1