Rockwell Automation 1783-Mxxx Stratix 8000 and 8300 Ethernet Managed Switches User Manual - Manual (Page 79)

Rockwell Automation Publication 1783-UM003I-EN-P - March 2014 79
Switch Software Features Chapter 3
In Figure 13 , E1 or E2 can be configured as the primary no-neighbor port.
Figure 13 - Example of Access Ring Topology
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.
You can configure REP only in networks 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 which neighbor port can
become the alternate port and which ports can 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.
E1 and E2 are configured
as edge no-neighbor ports
273792
REP ports
REP not
supported
E2
E1
REP Not Supported
REP Ports - Configured at
Transit Ports