REP

Why Use REP:

Procedures:

Tips on Using this Window:

  • Click the column headings to sort information.
  • Click Submit to save your changes.
  • Click Cancel to discard unsaved changes.

Back to the top

What Is REP

The Resilient Ethernet Protocol (REP) is a Cisco proprietary protocol that provides an alternative to Spanning Tree Protocol (STP) to control network loops, handle link failures, and improve convergence time. REP controls a group of ports connected in a segment, ensures that the segment does not create any bridging loops, and responds to link failures within the segment. REP provides a basis for constructing more complex networks and supports VLAN load balancing.

Cisco REP is a segment protocol. One REP segment is a chain of ports connected to each other and configured with a segment ID. Each segment consists of standard (non-edge) segment ports and two user-configured edge ports. A switch can have no more than two ports that belong to the same segment, and each segment port can have only one external neighbor. A segment can go through a shared medium, but on any link only two ports can belong to the same segment. REP is supported only on Layer 2 trunk interfaces. REP is supported on EtherChannels, but not on an individual port that belongs to an EtherChannel.

Cisco REP and STP can coexist on the same switch, but not on the same interface. REP does not interact with STP. For example, if a port is configured as a REP port, STP is disabled on that port. STP bridge protocol data units (BPDUs) are not accepted on or sent from segment ports REP ports. However, adjacent REP and STP rings or domains can share a common link. This common link can be used for passing REP and STP date plane traffic, or for the STP control plane traffic.

Back to the top

Configure REP Settings

The REP window shows the REP segments configured on the switch. To create a REP segment, set a segment ID and port type on the desired ports.

REP Admin VLAN

The administrative VLAN. The range is 2 to 4094. The default is VLAN 1.

REP ports are assigned to the same REP Admin VLAN. If the REP Admin VLAN changes, all REP ports are automatically assigned to the new REP Admin VLAN.

Interface

The number of the switch port, including port type (such as Fa for Fast Ethernet and Gi for Gigabit Ethernet), the base switch number (1), and the specific port number. For example: Fa1/1 is Fast Ethernet port 1 on the base switch.

Segment ID

The ID of the segment. The segment ID range is from 1 to 1024. If no segment ID is set, REP is disabled.

Port Type

The REP port type of the port can be: Primary, Edge, Transit, No-neighbor Primary, No-neighbor, and None. The default is None.

You must configure two edge ports on each REP segment, a primary edge port and a port to act as a secondary edge port. REP ports follow these rules:

  • If only one port on a switch is configured in a segment, the port should be an edge port.
  • If two ports on a switch belong to the same segment, both ports must be edge ports, or both ports must be regular segment ports.
  • If two ports on a switch belong to the same segment and one is configured as an edge port and one as a regular segment port (a misconfiguration), the edge port is treated as a regular segment port.
STCN Interface

Configure segment topology change notices (STCNs) for a port. The default is None.

TCNs are used within the segment to notify REP neighbors of topology changes. At the edge of the segment, REP can propagate the notification to the STP or to the other REP segments.

STCN Segment

Configure STCNs to a segment ID. The default is a blank field.

TCNs are used within the segment to notify REP neighbors of topology changes. At the edge of the segment, REP can propagate the notification to the STP or to the other REP segments.

STCN STP

Configure STCNs to a STP network. The default is an unchecked check box.

TCNs are used within the segment to notify REP neighbors of topology changes. At the edge of the segment, REP can propagate the notification to the STP or to the other REP segments.

Back to the top