Rockwell Automation 1783-BMxxx Stratix 5700 Ethernet Managed Switches User Manual - Manual (Page 110)

110 Rockwell Automation Publication 1783-UM004E-EN-P - June 2014
Chapter 3 Switch Software Features
In the following example, E1 or E2 can be configured as the primary no-neighbor
port.
Figure 8 - Ring Topology Example
REP has these limitations:
• You must configure each segment port; an incorrect configuration can
cause forwarding loops in the networks.
• REP can manage only a single failed port within the segment; multiple
port failures within the REP segment cause loss of network connectivity.
Configure REP in networks only with redundancy. Configuring REP in a
network without redundancy causes loss of connectivity.
Link Integrity
REP does not use an end-to-end polling mechanism between edge ports to verify
link integrity. It implements local link failure detection. The REP Link Status
Layer (LSL) detects its REP-aware neighbor and establishes connectivity within
the segment. All VLANs are blocked on an interface until it detects the neighbor.
After the neighbor is identified, REP determines the neighbor port to become
the alternate port and which ports forward traffic.
Each port in a segment has a unique port ID. The port ID format is similar to
that used by the spanning tree algorithm: a port number (unique on the bridge),
associated to a MAC address (unique in the network). When a segment port is
coming up, its LSL starts sending packets that include the segment ID and the
port ID. The port is declared as operational after it performs a three-way
handshake with a neighbor in the same segment.
273792
REP Not Supported
REP Ports Configured at Transit Ports
E1
E2