Hirschmann RS20 Operation & User’s Manual

Release 7.1 12/2011 Technical Support [email protected] User Manual Redundancy Configuration Industrial Ethernet (Gigabit) Switch RS20/RS30/RS40, MS20/MS30, OCTOPUS

not be taken to mean that these names may be considered as free in the sense of the trademark and tradename protection law and hence that they may be freely used by anyone. © 2011 Hirschmann Automation and Control GmbH Manuals and software are protected by copyright. All rights reserved. The copying, reproduction, translation, conversion into any electronic medium or machine scannable form is not permitted, either in whole or in part. An exception is the preparation of a backup copy of the software for your own use. For devices with embedded software, the end-user license agreement on the enclosed CD applies. The performance features described here are binding only if they have been expressly agreed when the contract was made. This document was produced by Hirschmann Automation and Control GmbH according to the best of the company's knowledge. Hirschmann reserves the right to change the contents of this document without prior notice. Hirschmann can give no guarantee in respect of the correctness or accuracy of the information in this document. Hirschmann can accept no responsibility for damages, resulting from the use of the network components or the associated operating software. In addition, we refer to the conditions of use specified in the license contract. You can get the latest version of this manual on the Internet at the Hirschmann product site (www.beldensolutions.com). Printed in Germany Hirschmann Automation and Control GmbH Stuttgarter Str. 45-51 72654 Neckartenzlingen Germany Tel.: +49 (0)1805 14-1538 Rel 7.1 12/2011 13.12.11

Release 7.1 12/2011 3 Contents About this Manual 5 Key 7 1 Introduction 9 1.1 Overview of Redundancy Topologies 10 1.2 Overview of Redundancy Protocols 11 2 Ring Redundancy 13 2.1 Example of a HIPER-Ring 15 2.1.1 Setting up and configuring the HIPER-Ring 17 2.2 Example of a MRP-Ring 21 3 Multiple Rings 27 4 Ring/Network Coupling 29 4.1 Variants of the ring/network coupling 30 4.2 Preparing a Ring/Network Coupling 32 4.2.1 Stand-by switch 32 4.2.2 One-Switch coupling 35 4.2.3 Two-Switch coupling 41 4.2.4 Two-Switch Coupling with Control Line 49 5 Spanning Tree 57 5.1 The Spanning Tree Protocol 59 5.1.1 The tasks of the STP 59 5.1.2 Bridge parameters 60 5.1.3 Bridge Identifier 60 5.1.4 Root Path Cost 61 5.1.5 Port Identifier 63 5.2 Rules for Creating the Tree Structure 64 5.2.1 Bridge information 64 5.2.2 Setting up the tree structure 64 5.3 Example of determining the root path 67 5.4 Example of manipulating the root path 69

Release 7.1 12/2011 5.5 Example of manipulating the tree structure 71 5.6 The Rapid Spanning Tree Protocol 72 5.6.1 Port roles 72 5.6.2 Port states 74 5.6.3 Spanning Tree Priority Vector 75 5.6.4 Fast reconfiguration 76 5.6.5 Configuring the Rapid Spanning Tree 77 5.7 Combining RSTP and MRP 87 5.7.1 Application example for the combination of RSTP and MRP 89 A Readers’ Comments 92 B Index 95 C Further Support 97

UM Redundancy Configuration L2E Release 7.1 12/2011 5 About this Manual The “Redundancy Configuration User Manual” document contains the information you require to select the suitable redundancy procedure and configure it. The “Basic Configuration” user manual contains the information you need to start operating the device. It takes you step by step from the first startup operation through to the basic settings for operation in your environment. The “Installation” user manual contains a device description, safety instructions, a description of the display, and the other information that you need to install the device. The “Industry Protocols” user manual describes how the device is connected by means of a communication protocol commonly used in the industry, such as EtherNet/IP and PROFINET IO. The “GUI” reference manual contains detailed information on using the graphical interface to operate the individual functions of the device. The “Command Line Interface” Reference Manual contains detailed information on using the Command Line Interface to operate the individual functions of the device.

6 UM Redundancy Configuration L2E Release 7.1 12/2011 The Industrial HiVision Network Management Software provides you with additional options for smooth configuration and monitoring:  Simultaneous configuration of multiple devices  Graphic interface with network layout  Auto-topology discovery  Event log  Event handling  Client/server structure  Browser interface  ActiveX control for SCADA integration  SNMP/OPC gateway.  Maintenance Hirschmann are continually working on improving and developing their software. You should regularly check whether there is a new version of the software that provides you with additional benefits. You will find software information and downloads on the product pages of the Hirschmann website.

Release 7.1 12/2011 7 Key The designations used in this manual have the following meanings: Symbols used:  List  Work step  Subheading Link Cross-reference with link Note: A note emphasizes an important fact or draws your attention to a dependency. Courier ASCII representation in user interface Execution in the Graphical User Interface (Web-based Interface user interface) Execution in the Command Line Interface user interface WLAN access point Router with firewall Switch with firewall Router Switch

Release 7.1 12/2011 Bridge Hub A random computer Configuration Computer Server PLC - Programmable logic controller I/O - Robot

Release 7.1 12/2011 9 1 Introduction The device contains a range of redundancy functions:  HIPER-Ring  MRP-Ring  Ring/Network coupling  Rapid Spanning Tree Algorithm (RSTP)

Topologies UM Redundancy Configuration L2E Release 7.1 12/2011 1.1 Overview of Redundancy Topologies To introduce redundancy onto layer 2 of a network, first clarify which network topology you require. Depending on the network topology selected, you then choose from the redundancy protocols that can be used with this network topology. The following topologies are possible: The Ring Redundancy Protocol MRP has particular properties to offer:  You have the option of coupling to MRP-Rings other ring structures that work with RSTP (see on page 87 “Combining RSTP and MRP”). Network topology Possible redundancy procedures Comments Tree structure without loops (cycle-free) Only possible in connection with physical loops - Topology with 1 loop RSTP Ring Redundancy Ring Redundancy procedures (HIPER-Ring, Fast HIPER-Ring or MRP) provide shorter switching times than RSTP. Topology with 2 loops RSTP Ring Redundancy Ring redundancy: an MRP-Ring with an RSTP- Ring. Topology with 3 non-nested loops RSTP Ring Redundancy Ring coupling The ring coupling provides particular support when redundantly coupling a redundant ring to another redundant ring, or to any structure that only works with Hirschmann devices Table 1: Overview of Redundancy Topologies

Release 7.1 12/2011 1.2 Overview of Redundancy Protocols 11 1.2 Overview of Redundancy Protocols Note: When you are using a redundancy function, you deactivate the flow control on the participating ports. Default setting: flow control deactivated globally and activated on all ports. If the flow control and the redundancy function are active at the same time, the redundancy may not work as intended. Redundancy procedure Network topology Switch-over time RSTP Random structure typically < 1 s (STP < 30 s), up to < 30 s - depends heavily on the number of devices Note: Up to 79 devices possible, depending on topology and configuration. If the default values (factory settings) are used, up to 39 devices are possible, depending on the topology (see page 57). HIPER-Ring Ring typically 80 ms, up to < 500 ms or < 300 ms (selectable) - the number of switches has a minimal effect on the switch-over time MRP-Ring Ring typically 80 ms, up to < 500 ms or < 200 ms (selectable) - the number of switches has a minimal effect on the switch over time Note: In combination with RSTP in MRP compatibility mode, up to 39 devices are possible, depending on the configuration. If the default values (factory settings) for RSTP are being used, up to 19 devices are possible (see page 57). Table 2: Comparison of the redundancy procedures

Redundancy Protocols UM Redundancy Configuration L2E Release 7.1 12/2011

Release 7.1 12/2011 13 2 Ring Redundancy The concept of ring redundancy allows the construction of high-availability, ring-shaped network structures. With the help of the RM (Ring Manager) function, the two ends of a backbone in a line structure can be closed to a redundant ring. The ring manager keeps the redundant line open as long as the line structure is intact. If a segment becomes inoperable, the ring manager immediately closes the redundant line, and line structure is intact again. Figure 1: Line structure Figure 2: Redundant ring structure RM = Ring Manager —— main line - - - redundant line RM

Release 7.1 12/2011 If a section is down, the ring structure of a  HIPER-(HIGH PERFORMANCE REDUNDANCY) Ring with up to 50 devices typically transforms back to a line structure within 80 ms (possible settings: standard/accelerated).  MRP (Media Redundancy Protocol) Ring (IEC 62439) of up to 50 devices typically transforms back to a line structure within 80 ms (adjustable to max. 200 ms/500 ms). Devices with HIPER-Ring function capability:  Within a HIPER-Ring, you can use any combination of the following devices: – RS1 – RS2-./. – RS2-16M – RS2-4R – RS20, RS30, RS40 – RSR20, RSR30 – OCTOPUS – MICE – MS20, MS30 – PowerMICE – MACH 100 – MACH 1000 – MACH 1040 – MACH 3000 – MACH 4000  Within an MRP-Ring, you can use devices that support the MRP protocol based on IEC62439. Note: Only one Ring Redundancy method can be enabled on one device at any one time. When changing to another Ring Redundancy method, deactivate the function for the time being. Note: The following usage of the term “ring manager” instead of “redundancy manager” makes the function easier to understand.

Release 7.1 12/2011 2.1 Example of a HIPER-Ring 15 2.1 Example of a HIPER-Ring A network contains a backbone in a line structure with 3 devices. To increase the redundancy reliability of the backbone, you have decided to convert the line structure to a HIPER-Ring. You use ports 1.1 and 1.2 of the devices to connect the lines1. Figure 3: Example of HIPER-Ring RM = Ring Manager —— main line - - - redundant line The following example configuration describes the configuration of the ring manager device (1). The two other devices (2 to 3) are configured in the same way, but without activating the ring manager function. Select the “Standard” value for the ring recovery, or leave the field empty. 1. On modular devices the 1st number of the port designation specifies the module. The 2nd number specifies the port on the module. The specification pattern 1.x is also used on non-modular devices for consistency. RM 1 2 3 1.1 1.2 1.1 1.2 1.1 1.2

UM Redundancy Configuration L2E Release 7.1 12/2011 Note: As an alternative to using software to configure the HIPER-Ring, with devices RS20/30/40 and MS20/30 you can also use DIP switches to enter a number of settings on the devices. You can also use a DIP switch to enter a setting for whether the configuration via DIP switch or the configuration via software has priority. The state on delivery is “Software Configuration”. You will find details on the DIP switches in the “Installation” user manual. Note: Configure all the devices of the HIPER-Ring individually. Before you connect the redundant line, you must complete the configuration of all the devices of the HIPER-Ring. You thus avoid loops during the configuration phase.

Release 7.1 12/2011 2.1 Example of a HIPER-Ring 17 2.1.1 Setting up and configuring the HIPER-Ring  Set up the network to meet your demands.  Configure all ports so that the transmission speed and the duplex settings of the lines correspond to the following table: Note: When activating the HIPER-Ring function via software or DIP switches, the device sets the corresponding settings for the pre-defined ring ports in the configuration table (transmission rate and mode). If you switch off the HIPER-Ring function, the ports, which are changed back into normal ports, keep the ring port settings. Independently of the DIP switch setting, you can still change the port settings via the software. Port type Bit rate Autonegotiation (automatic configuration) Port setting Duplex TX 100 Mbit/s off on 100 Mbit/s full duplex (FDX) TX 1 Gbit/s on on - Optical 100 Mbit/s off on 100 Mbit/s full duplex (FDX) Optical 1 Gbit/s on on - Optical 10 Gbit/s - on 10 Gbit/s full duplex (FDX) Table 3: Port settings for ring ports  Select the Redundancy:Ring Redundancy dialog.  Under “Version”, select HIPER-Ring.  Define the desired ring ports 1 and 2 by making the corresponding entries in the module and port fields. If it is not possible to enter a module, then there is only one module in the device that is taken over as a default.

UM Redundancy Configuration L2E Release 7.1 12/2011 Display in “Operation” field: – active: This port is switched on and has a link. – inactive: This port is switched off or it has no link. Figure 4: Ring Redundancy dialog  Activate the ring manager for this device. Do not activate the ring manager for any other device in the HIPER-Ring.  In the “Ring Recovery” frame, select the value “Standard” (default). Note: Settings in the “Ring Recovery” frame are only effective for devices that you have configured as ring managers.  Click “Set” to temporarily save the entry in the configuration.

Release 7.1 12/2011 2.1 Example of a HIPER-Ring 19  Now proceed in the same way for the other two devices. Note: If you have configured VLANS, note the VLAN configuration of the ring ports. In the configuration of the HIPER-Ring, you select for the ring ports – VLAN ID 1 and “Ingress Filtering” disabled in the port table and – VLAN membership U in the static VLAN table. Note: Deactivate the Spanning Tree protocol for the ports connected to the HIPER-Ring, because Spanning Tree and Ring Redundancy affect each other. enable Switch to the privileged EXEC mode. configure Switch to the Configuration mode. hiper-ring mode ring-manager Select the HIPER-Ring ring redundancy and define the device as ring manager. Switch's HIPER Ring mode set to ring-manager hiper-ring port primary 1/1 Define port 1 in module 1 as ring port 1. HIPER Ring primary port set to 1/1 hiper-ring port secondary 1/2 Define port 2 in module 1 as ring port 2. HIPER Ring secondary port set to 1/2 exit Switch to the privileged EXEC mode. show hiper-ring Display the HIPER-Ring parameters. HIPER Ring Mode of the Switch.................. ring-manager configuration determined by.................. management HIPER Ring Primary Port of the Switch.......... 1/1, state active HIPER Ring Secondary Port of the Switch........ 1/2, state active HIPER Ring Redundancy Manager State............ active HIPER Ring Redundancy State (red. exists).. no (rm is active) HIPER Ring Setup Info (Config. failure)........ no error HIPER Ring Recovery Delay...................... 500ms

UM Redundancy Configuration L2E Release 7.1 12/2011 If you used the DIP switch to activate the function of HIPER-Ring, RSTP is automatically switched off.  Now you connect the line to the ring. To do this, you connect the 2 devices to the ends of the line using their ring ports. Note: If you want to use link aggregation connections in the HIPER-Ring (PowerMICE and MACH 4000), you enter the index of the desired link aggregation entry for the module and the port. The displays in the “Redundancy Manager Status” frame mean: – “Active (redundant line)”: The ring is open, which means that a data line or a network component within the ring is down. – “Inactive”: The ring is closed, which means that the data lines and network components are working. The displays in the “Information” frame mean – “Redundancy existing”: One of the lines affected by the function may be interrupted, with the redundant line then taking over the function of the interrupted line. – "Configuration failure”: The function is incorrectly configured or the cable connections at the ring ports are improperly configured (e.g., not plugged into the ring ports).

Release 7.1 12/2011 2.2 Example of a MRP-Ring 21 2.2 Example of a MRP-Ring A network contains a backbone in a line structure with 3 devices. To increase the availability of the backbone, you decide to convert the line structure to a redundant ring. In contrast to the previous example, devices from different manufacturers are used which do not all support the HIPER-Ring protocol. However, all devices support MRP as the ring redundancy protocol, so you decide to deploy MRP. You use ports 1.1 and 2.2 of the devices to connect the lines. Figure 5: Example of MRP-Ring RM = Ring Manager —— main line - - - redundant line The following example configuration describes the configuration of the ring manager device (1). You configure the 2 other devices (2 to 3) in the same way, but without activating the ring manager function. This example does not use a VLAN. You have entered 200 ms as the ring recovery time, and all the devices support the advanced mode of the ring manager. RM 1 2 3 1.1 1.2 1.1 1.2 1.1 1.2

UM Redundancy Configuration L2E Release 7.1 12/2011 Note: For devices with DIP switches, put all DIP switches to “On”. The effect of this is that you can use the software configuration to configure the redundancy function without any restrictions. You thus avoid the possibility of the software configuration being hindered by the DIP switches. Note: Configure all the devices of the MRP-Ring individually. Before you connect the redundant line, you must have completed the configuration of all the devices of the MRP-Ring. You thus avoid loops during the configuration phase.  Set up the network to meet your demands.  Configure all ports so that the transmission speed and the duplex settings of the lines correspond to the following table: Port type Bit rate Autonegotiation (automatic configuration) Port setting Duplex TX 100 Mbit/s off on 100 Mbit/s full duplex (FDX) TX 1 Gbit/s on on - Optical 100 Mbit/s off on 100 Mbit/s full duplex (FDX) Optical 1 Gbit/s on on - Optical 10 Gbit/s - on 10 Gbit/s full duplex (FDX) Table 4: Port settings for ring ports  Select the Redundancy:Ring Redundancy dialog.  Under “Version”, select MRP.  Define the desired ring ports 1 and 2 by making the corresponding entries in the module and port fields. If it is not possible to enter a module, then there is only one module in the device that is taken over as a default.

Release 7.1 12/2011 2.2 Example of a MRP-Ring 23 Display in “Operation” field:  forwarding: this port is switched on and has a link.  blocked: this port is blocked and has a link  disabled: this port is disabled  not-connected: this port has no link Figure 6: Ring Redundancy dialog  In the “Ring Recovery” frame, select 200 ms. Note: If selecting 200 ms for the ring recovery does not provide the ring stability necessary to meet the requirements of your network, you select 500 ms. Note: Settings in the “Ring Recovery” frame are only effective for devices that you have configured as ring managers.  Under “Configuration Redundancy Manager”, activate the advanced mode.  Activate the ring manager for this device. Do not activate the ring manager for any other device in the MRP-Ring.  Leave the VLAN ID as 0 in the VLAN field.  Switch the operation of the MRP-Ring on.  Click “Set” to temporarily save the entry in the configuration.

UM Redundancy Configuration L2E Release 7.1 12/2011 Note: If you want to use the RSTP (see on page 57 “Spanning Tree”) redundancy protocol in an MRP-Ring, switch on the MRP compatibility on all devices in the MRP-Ring in the Rapid Spanning Tree:Global dialog as the RSTP (Spanning-Tree) and ring redundancy affect each other. If this is not possible, perhaps because individual devices do not support the MRP compatibility, you deactivate RSTP at the ports connected to the MRP- Ring. Note: When you are configuring an MRP-Ring using the Command Line Interface, you define an additional parameter. When configured using CLI, an MRP-Ring is addressed via its MRP domain ID. The MRP domain ID is a sequence of 16 number blocks (8-bit values). Use the default domain of 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 for the MRP domain ID. This default domain is also used internally for a configuration via the Web- based interface. Configure all the devices within an MRP-Ring with the same MRP domain ID. The displays in the “Information” frame mean – “Redundancy existing”: One of the lines affected by the function may be interrupted, with the redundant line then taking over the function of the interrupted line. – "Configuration failure”: The function is incorrectly configured or the cable connections at the ring ports are improperly configured (e.g., not plugged into the ring ports). The “VLAN” frame enables you to assign the MRP-Ring to a VLAN:  If VLANs are configured, you make the following selections in the "VLAN" frame: – VLAN ID 0, if the MRP-Ring configuration is not to be assigned to a VLAN, as in this example. Select VLAN ID 1 and VLAN membership U (Untagged) in the static VLAN table for the ring ports. – A VLAN ID > 0, if the MRP-Ring configuration is to be assigned to this VLAN. For all devices in this MRP-Ring, enter this VLAN ID in the MRP-Ring configuration, and then choose this VLAN ID and the VLAN membership Tagged (T) in the static VLAN table for all ring ports in this MRP-Ring.

Release 7.1 12/2011 2.2 Example of a MRP-Ring 25 enable Switch to the privileged EXEC mode. configure Switch to the Configuration mode. mrp new-domain default-domain Creates a new MRP-Ring with the default domain ID 255.255.255.255.255.255.255.255.255.255.255. 255.255.255.255.255. MRP domain created: Domain ID: 255.255.255.255.255.255.255.255.255.255.255.255.255.255.255.255 (Default MRP domain) mrp current-domain port primary 1/1 Define port 1 in module 1 as ring port 1 (primary). Primary Port set to 1/1 mrp current-domain port secondary 1/2 Define port 2 in module 1 as ring port 2 (secondary) Secondary Port set to 1/2

UM Redundancy Configuration L2E Release 7.1 12/2011  Now you connect the line to the ring. To do this, you connect the 2 devices to the ends of the line using their ring ports. mrp current-domain mode manager Define this device as the ring manager. Mode of Switch set to manager mrp current-domain recovery- delay 200ms Define 200ms as the value for the “Ring Recovery”. Recovery delay set to 200ms mrp current-domain advanced- mode enable Activate the “MRP Advanced Mode”. Advanced Mode (react on link change) set to Enabled mrp current-domain operation enable Activate the MRP-Ring. Operation set to Enabled exit Go back one level. show mrp Show the current parameters of the MRP-Ring (abbreviated display). Domain ID: 255.255.255.255.255.255.255.255.255.255.255.255.255.255.255.255 (Default MRP domain) Configuration Settings: Advanced Mode (react on link change).... Enabled Manager Priority........................ 32768 Mode of Switch (administrative setting). Manager Mode of Switch (real operating state)... Manager Domain Name............................. Recovery delay.......................... 200ms Port Number, Primary.................... 1/1, State: Not Connected Port Number, Secondary.................. 1/2, State: Not Connected VLAN ID................................. 0 (No VLAN) Operation............................... Enabled

Release 7.1 12/2011 27 3 Multiple Rings The device allows you to set up multiple rings with different redundancy protocols:  You have the option of coupling to MRP-Rings other ring structures that work with RSTP (see on page 87 “Combining RSTP and MRP”).

Release 7.1 12/2011 29 4 Ring/Network Coupling Ring/Network Coupling allows the redundant coupling of redundant rings and network segments. Ring/Network Coupling connects 2 rings/network segments via 2 separate paths. The ring/network coupling supports the coupling of a ring (HIPER-Ring, Fast HIPER-Ring or MRP) to a second ring (also HIPER-Ring, Fast HIPER-Ring or MRP) or to a network segment of any structure, when all the devices in the coupled network are Hirschmann devices. The ring/network coupling supports the following devices:  RS2-./.  RS2-16M  RS20, RS30, RS40  OCTOPUS  MICE (from rel. 3.0)  PowerMICE  MS20, MS30  RSR20, RSR30  MACH 100  MACH 1000  MACH 1040  MACH 3000 (from Rel. 3.3),  MACH 4000

coupling UM Redundancy Configuration L2E Release 7.1 12/2011 4.1 Variants of the ring/network coupling The redundant coupling is effected by the one-Switch coupling of two ports of one device in the first ring/network segment to one port each of two devices in the second ring/network segment (see fig. 8). One of the two connections – the redundant one – is blocked for normal data traffic in normal operation. If the main line no longer functions, the device opens the redundant line immediately. If the main line functions again, the redundant line is again blocked for normal data traffic and the main line is used again. The ring coupling detects and handles an error within 500 ms (typically 150 ms). The redundant coupling is effected by the two-switch coupling of one port each from two devices in the first ring/network segment to one port each of two devices in the second ring/network segment (see fig. 14). The device in the redundant line and the device in the main line use control packets to inform each other about their operating states, via the Ethernet or the control line. If the main line no longer functions, the redundant device (slave) opens the redundant line immediately. As soon as the main line is working again, the device in the main line informs the redundant device of this. The redundant line is again blocked for normal data traffic and the main line is used again. The ring coupling detects and handles an error within 500 ms (typically 150 ms). The type of coupling configuration is primarily determined by the topological conditions and the desired level of availability (see table 5).

Release 7.1 12/2011 4.1 Variants of the ring/network coupling 31 Note: Choose a configuration based on topological conditions and the level of availability you require (see table 5). One-Switch coupling Two-Switch coupling Two-Switch coupling with control line Application The 2 devices are in impractical topological positions. Therefore, putting a line between them would involve a lot of effort for two-Switch coupling. The 2 devices are in practical topological positions. Installing a control line would involve a lot of effort. The 2 devices are in practical topological positions. Installing a control line would not involve much effort. Disadvantage If the Switch configured for the redundant coupling becomes inoperable, no connection remains between the networks. More effort for connecting the 2 devices to the network (compared with one- Switch coupling). More effort for connecting the two devices to the network (compared with one- Switch and two-Switch coupling). Advantage Less effort involved in connecting the 2 devices to the network (compared with two- Switch coupling). If one of the devices configured for the redundant coupling becomes inoperable, the coupled networks are still connected. If one of the devices configured for the redundant coupling becomes inoperable, the coupled networks are still connected. Table 5: Selection criteria for the configuration types for redundant coupling

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 4.2.1 Stand-by switch All devices have a stand-by switch, with which you can define the role of the device within a Ring/Network coupling. Depending on the device type, this switch is a DIP switch on the devices, or else it is exclusively a software setting (Redundancy:Ring/Network Coupling dialog). By setting this switch, you define whether the device has the main coupling or the redundant coupling role within a Ring/Network coupling. You will find details on the DIP switches in the “Installation” user manual. Depending on the device and model, set the stand-by switch in accordance with the following table: Device type Stand-by switch type RS2-./. DIP switch RS2-16M DIP switch RS20/RS30/RS40 Selectable: DIP switch and software setting MICE/Power MICE Selectable: DIP switch and software setting MS20/MS30 Selectable: DIP switch and software setting OCTOPUS Software switch RSR20/RSR30 Software switch MACH 100 Software switch MACH 1000 Software switch MACH 3000/MACH 4000 Software switch Table 6: Overview of the stand-by switch types

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 33 Note: In the following screenshots and diagrams, the following conventions are used:  Blue indicates devices or connections of the items currently being described  Black indicates devices or connections that connect to the items currently being described  Thick lines indicate connections of the items currently being described  This lines indicate connections which connect to the items currently being described  Lines of dashes indicate a redundant connection  Dotted lines indicate the control line. Device with Choice of main coupling or redundant coupling DIP switch On “Stand-by” DIP switch DIP switch/software switch option According to the option selected - on “Stand-by” DIP switch or in the - Redundancy:Ring/Network Coupling dialog, by making selection in “Select configuration”. Note: These devices have a DIP switch, with which you can choose between the software configuration and the DIP switch configuration. You can find details on the DIP switches in the User Manual Installation. Software switch In the Redundancy:Ring/Network Coupling dialog Table 7: Setting the stand-by switch  Select the Redundancy:Ring/Network Coupling dialog.  You first select the configuration you want: One-Switch coupling (“1”), two-Switch coupling (“2”) or two-Switch coupling with control line (“3”), (see fig. 7).

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 Note: For reasons of redundancy reliability, do not use Rapid Spanning Tree and Ring/Network Coupling in combination. Figure 7: Choosing the ring coupling configuration (when the DIP switch is off, or for devices without a DIP switch) For devices without DIP switches, the software settings are not restricted. For devices with DIP switches, depending on the DIP switch position, the dialog displays the possible configurations in color, while those configurations that are not possible appear in gray. The possible configurations are:  DIP switch RM: ON or OFF, Stand-by: OFF: Two-Switch coupling as master (with or without control line)  DIP switch RM: OFF, Stand-by: ON: One-Switch coupling and two-Switch coupling as slave (with or without control line)  DIP switch RM: ON, Stand-by: ON: DIP switches are deactivated, and the software settings are possible without any restrictions If the DIP switches are activated and you want to use the software to select one of the configurations that are not possible (grayed-out), you put the DIP switches on the device into another position and reload the dialog.

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 35 4.2.2 One-Switch coupling Figure 8: Example of one-Switch coupling 1: Backbone 2: Ring 3: Partner coupling port 4: Coupling port 5: Main Line 6: Redundant Line RM RM 3 5 4 6 1 2 STAND-BY ON

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 The coupling between two networks is performed by the main line (solid blue line) in the normal mode of operation, which is connected to the partner coupling port. If the main line becomes inoperable, the redundant line (dashed blue line), which is connected to the coupling port, takes over the ring/network coupling. The coupling switch-over is performed by one Switch.  Select the Redundancy:Ring/Network Coupling dialog.  Select "One-Switch coupling" by means of the dialog button with the same graphic as below (see fig. 9). Figure 9: One-Switch-coupling 1: Coupling port 2: Partner coupling port The following settings apply to the switch displayed in blue in the selected graphic.  Select the partner coupling port (see fig. 10). .With “Partner coupling port” you specify at which port you are connecting the control line. You will find the port assignment for the redundant coupling in table 8. 2 1 STAND-BY ON

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 37 The following tables show the selection options and default settings for the ports used in the Ring/Network coupling. Device Partner coupling port Coupling port RS2-./. Not possible Not possible RS2-16M All ports (default setting: port 2) All ports (default setting: port 1) RS20, RS30, RS40 All ports (default setting: port 1.3) All ports (default setting: port 1.4) OCTOPUS All ports (default setting: port 1.3) All ports (default setting: port 1.4) MICE All ports (default setting: port 1.3) All ports (default setting: port 1.4) PowerMICE All ports (default setting: port 1.3) All ports (default setting: port 1.4) MS20 All ports (default setting: port 1.3) All ports (default setting: port 1.4) MS30 All ports (default setting: port 2.3) All ports (default setting: port 2.4) RSR20/30 All ports (default setting: port 1.3) All ports (default setting: port 1.4) MACH 100 All ports (default setting: port 2.3) All ports (default setting: port 2.4) MACH 1000 All ports (default setting: port 1.3) All ports (default setting: port 1.4) MACH 3000 All ports All ports MACH 4000 All ports (default setting: port 1.3) All ports (default setting: port 1.4) Table 8: Port assignment for one-Switch coupling Note: Configure the partner coupling port and the ring redundancy ports on different ports.  Select the coupling port (see fig. 10). With “Coupling port” you specify at which port you are connecting the network segments: You will find the port assignment for the redundant coupling in table 8. Note: Configure the coupling port and the redundancy ring ports on different ports.  Activate the function in the “Operation” frame (see fig. 10)  Now connect the redundant line. The displays in the “Select port” frame mean: – “Port mode”: The port is either active or in stand-by mode. – “Port state”: The port is either connected or not connected.

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 The displays in the “Information” frame mean: – “Redundancy guaranteed”: If the main line no longer functions, the redundant line takes over the function of the main line. – “Configuration failure”: The function is incomplete or incorrectly configured. Figure 10: One-Switch coupling: Selecting the port and enabling/disabling operation Note: The following settings are required for the coupling ports (you select the Basic Settings:Port Configuration dialog): See table on 17 “Port settings for ring ports”. Note: If VLANs are configured, set the coupling and partner coupling ports’ VLAN configuration as follows: – in the dialog Switching:VLAN:Port Port VLAN ID 1 and „Ingress Filtering“ deactivated – in the dialog Switching:VLAN:Static VLAN-Membership U (Untagged) Redundancy mode  In the “Redundancy Mode” frame, select (see fig. 11) – “Redundant Ring/Network Coupling” or – “Extended Redundancy”.

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 39 Figure 11: One-Switch coupling: Selecting the redundancy mode With the “Redundant Ring/Network Coupling” setting, either the main line or the redundant line is active. The lines are never both active at the same time. With the “Extended Redundancy” setting, the main line and the redundant line are simultaneously active if the connection line between the devices in the connected (i.e., remote) network becomes inoperable (see fig. 12). During the reconfiguration period, packet duplications may occur. Therefore, select this setting only if your application detects package duplications. Figure 12: Extended redundancy Coupling mode The coupling mode indicates the type of the connected network.  In the “Coupling Mode” frame, select (see fig. 13) – “Ring Coupling” or – “Network Coupling”

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 Figure 13: One-Switch coupling: Selecting the coupling mode  Select "Ring coupling" if you are connecting to a redundancy ring.  Select "Network Coupling" if you are connecting to a line or tree structure. Delete coupling configuration  The “Delete coupling configuration” button in the dialog allows you to reset all the coupling settings of the device to the state on delivery.

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 41 4.2.3 Two-Switch coupling Figure 14: Example of two-Switch coupling 1: Backbone 2: Ring 3: Main line 4: Redundant line RM RM 3 4 1 2 STAND-BY ON STAND-BY ON

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 The coupling between 2 networks is performed by the main line (solid blue line). If the main line or one of the adjacent Switches becomes inoperable, the redundant line (dashed black line) takes over coupling the 2 networks. The coupling is performed by two Switches. The switches send their control packages over the Ethernet. The Switch connected to the main line, and the Switch connected to the redundant line are partners with regard to the coupling.  Connect the two partners via their ring ports.  Select the Redundancy:Ring/Network Coupling dialog.  Select "Two-Switch coupling“ by means of the dialog button with the same graphic as below (see fig. 15). Figure 15: Two-Switch coupling 1: Coupling port 2: Partner coupling port The following settings apply to the switch displayed in blue in the selected graphic.  Select the coupling port (see fig. 16). With “Coupling port” you specify at which port you are connecting the network segments: You will find the port assignment for the redundant coupling in table 9.  For a device with DIP switches, you switch the stand-by switch to OFF or deactivate the DIP switches. Connect the main line to the coupling port. 1 2 STAND-BY ON

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 43 Note: Configure the coupling port and the redundancy ring ports on different ports. Device Coupling port RS2-./. Not possible RS2-16M Adjustable for all ports (default setting: port 1) RS20, RS30, RS40 Adjustable for all ports (default setting: port 1.4) OCTOPUS Adjustable for all ports (default setting: port 1.4) MICE Adjustable for all ports (default setting: port 1.4) PowerMICE Adjustable for all ports (default setting: port 1.4) MS20 Adjustable for all ports (default setting: port 1.4) MS30 Adjustable for all ports (default setting: port 2.4) RSR20/30 Adjustable for all ports (default setting: port 1.4) MACH 100 Adjustable for all ports (default setting: port 2.4) MACH 1000 Adjustable for all ports (default setting: port 1.4) MACH 3000 Adjustable for all ports MACH 4000 Adjustable for all ports (default setting: port 1.4) Table 9: Port assignment for the redundant coupling (two-Switch coupling)  Activate the function in the “Operation” frame (see fig. 16)  Now connect the redundant line. The displays in the “Select port” frame mean: – “Port mode”: The port is either active or in stand-by mode. – “Port state”: The port is either connected or not connected. – “IP Address”: The IP address of the partner, if the partner is already operating in the network. The displays in the “Information” frame mean: – “Redundancy guaranteed”: If the main line no longer functions, the redundant line takes over the function of the main line. – “Configuration failure”: The function is incomplete or incorrectly configured.

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 Note: If you are operating the Ring Manager and two-Switch coupling functions at the same time, there is the possibility of creating a loop. Figure 16: Two-Switch coupling: Selecting the port and enabling/disabling operation To avoid continuous loops, the Switch sets the port state of the coupling port to “off” if you: – switch off the operation setting or – change the configuration while the connections are in operation at these ports. Note: The following settings are required for the coupling ports (you select the Basic Settings:Port Configuration dialog): See table on 17 “Port settings for ring ports”. Note: If VLANs are configured, set the coupling and partner coupling ports’ VLAN configuration as follows: – in the dialog Switching:VLAN:Port Port VLAN ID 1 and „Ingress Filtering“ deactivated – in the dialog Switching:VLAN:Static VLAN-Membership U (Untagged)

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 45 Note: Configure the coupling port and the redundancy ring ports on different ports.  Select "Two-Switch coupling“ by means of the dialog button with the same graphic as below (see fig. 17). Figure 17: Two-Switch coupling 1: Coupling port 2: Partner coupling port The following settings apply to the switch displayed in blue in the selected graphic.  Select the coupling port (see fig. 16). With “Coupling port” you specify at which port you are connecting the network segments: You will find the port assignment for the redundant coupling in table 9.  For a device with DIP switches, you switch the stand-by switch to ON or deactivate the DIP switches. You connect the redundant line to the coupling port. 2 1 STAND-BY ON

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011  Activate the function in the “Operation” frame (see fig. 16) The displays in the “Select port” frame mean: – “Port mode”: The port is either active or in stand-by mode. – “Port state”: The port is either connected or not connected. – “IP Address”: The IP address of the partner, if the partner is already operating in the network. The displays in the “Information” frame mean: – “Redundancy guaranteed”: If the main line no longer functions, the redundant line takes over the function of the main line. – “Configuration failure”: The function is incomplete or incorrectly configured. To avoid continuous loops, the Switch sets the port state of the coupling port to "off” if you:: – switch off operation or – change the configuration while the connections are in operation at these ports. Note: The following settings are required for the coupling ports (you select the Basic Settings:Port Configuration dialog): See table on 17 “Port settings for ring ports”. Note: If VLANs are configured, set the coupling and partner coupling ports’ VLAN configuration as follows: – in the dialog Switching:VLAN:Port Port VLAN ID 1 and „Ingress Filtering“ deactivated – in the dialog Switching:VLAN:Static VLAN-Membership U (Untagged) Note: If you are operating the Ring Manager and two-Switch coupling functions at the same time, there is the possibility of creating a loop.

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 47 Redundancy mode  In the “Redundancy Mode” frame, select (see fig. 18) – “Redundant Ring/Network Coupling” or – “Extended Redundancy”. Figure 18: Two-Switch coupling: Selecting the redundancy mode With the “Redundant Ring/Network Coupling” setting, either the main line or the redundant line is active. The lines are never both active at the same time. With the “Extended Redundancy” setting, the main line and the redundant line are simultaneously active if the connection line between the devices in the connected (i.e. remote) network fails (see fig. 12). During the reconfiguration period, package duplications may occur. Therefore, only select this setting if your application detects package duplications. Figure 19: Extended redundancy

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 Coupling mode The coupling mode indicates the type of the connected network.  In the “Coupling Mode” frame, select (see fig. 20) – “Ring Coupling” or – “Network Coupling” Figure 20: Two-Switch coupling: Selecting the coupling mode  Select "Ring coupling" if you are connecting to a redundancy ring.  Select "Network Coupling" if you are connecting to a line or tree structure. Delete coupling configuration  The “Delete coupling configuration” button in the dialog allows you to reset all the coupling settings of the device to the state on delivery.

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 49 4.2.4 Two-Switch Coupling with Control Line Figure 21: Example of Two-Switch coupling with control line 1: Backbone 2: Ring 3: Main line 4: Redundant line 5: Control line RM RM 3 4 5 1 2 STAND-BY ON STAND-BY ON

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 The coupling between 2 networks is performed by the main line (solid blue line). If the main line or one of the adjacent Switches becomes inoperable, the redundant line (dashed black line) takes over coupling the 2 networks. The coupling is performed by two Switches. The Switches send their control packets over a control line (dotted line). The Switch connected to the main line, and the Switch connected to the redundant line are partners with regard to the coupling.  Connect the two partners via their ring ports.  Select the Redundancy:Ring/Network Coupling dialog.  Select „Two-Switch coupling with control line“ by means of the dialog button with the same graphic as below (see fig. 22). Figure 22: Two-Switch coupling with control line 1: Coupling port 2: Partner coupling port 3: Control line The following settings apply to the switch displayed in blue in the selected graphic.  Select the coupling port (see fig. 23). With “Coupling port” you specify at which port you are connecting the network segments: You will find the port assignment for the redundant coupling in table 10.  For a device with DIP switches, you switch the stand-by switch to OFF or deactivate the DIP switches. Connect the main line to the coupling port. 1 2 3 STAND-BY ON

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 51 Note: Configure the coupling port and the redundancy ring ports on different ports.  Select the control port (see fig. 23) With “Control port” you specify at which port you are connecting the control line. You will find the port assignment for the redundant coupling in table 10. Device Coupling port Control port RS2-./. Port 1 Stand-by port (can only be combined with RS2-../.. ) RS2-16M Adjustable for all ports (default setting: port 1) Adjustable for all ports (default setting: port 2) RS20, RS30, RS40 Adjustable for all ports (default setting: port 1.4) Adjustable for all ports (default setting: port 1.3) OCTOPUS Adjustable for all ports (default setting: port 1.4) Adjustable for all ports (default setting: port 1.3) MICE Adjustable for all ports (default setting: port 1.4) Adjustable for all ports (default setting: port 1.3) PowerMICE Adjustable for all ports (default setting: port 1.4) Adjustable for all ports (default setting: port 1.3) MS20 Adjustable for all ports (default setting: port 1.4) Adjustable for all ports (default setting: port 1.3) MS30 Adjustable for all ports (default setting: port 2.4) Adjustable for all ports (default setting: port 2.3) RSR20/RSR30 Adjustable for all ports (default setting: port 1.4) Adjustable for all ports (default setting: port 1.3) MACH 100 Adjustable for all ports (default setting: port 2.4) Adjustable for all ports (default setting: port 2.3) MACH 1000 Adjustable for all ports (default setting: port 1.4) Adjustable for all ports (default setting: port 1.3) MACH 3000 Adjustable for all ports Adjustable for all ports MACH 4000 Adjustable for all ports (default setting: port 1.4) Adjustable for all ports (default setting: port 1.3) Table 10: Port assignment for the redundant coupling (two-Switch coupling with control line)

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011  Activate the function in the “Operation” frame (see fig. 23)  Now connect the redundant line and the control line. The displays in the “Select port” frame mean: – “Port mode”: The port is either active or in stand-by mode. – “Port state”: The port is either connected or not connected. – “IP Address”: The IP address of the partner, if the partner is already operating in the network. The displays in the “Information” frame mean: – “Redundancy guaranteed”: If the main line no longer functions, the redundant line takes over the function of the main line. – “Configuration failure”: The function is incomplete or incorrectly configured. Figure 23: Two-Switch coupling with control line: Selecting the port and enabling/disabling operation To avoid continuous loops, the Switch sets the port state of the coupling port to “off” if you: – switch off the operation setting or – change the configuration while the connections are in operation at these ports.

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 53 Note: The following settings are required for the coupling ports (you select the Basic Settings:Port Configuration dialog): See table on 17 “Port settings for ring ports”. Note: If VLANs are configured, set the coupling and partner coupling ports’ VLAN configuration as follows: – in the dialog Switching:VLAN:Port Port VLAN ID 1 and „Ingress Filtering“ deactivated – in the dialog Switching:VLAN:Static VLAN-Membership U (Untagged)  Select "Two-Switch coupling with control line“ by means of the dialog button with the same graphic as below (see fig. 24). Figure 24: Two-Switch coupling with control line 1: Coupling port 2: Partner coupling port 3: Control line The following settings apply to the switch displayed in blue in the selected graphic.  Select the coupling port (see fig. 23). With “Coupling port” you specify at which port you are connecting the network segments: You will find the port assignment for the redundant coupling in table 10.  For a device with DIP switches, you switch the stand-by switch to ON or deactivate the DIP switches. You connect the redundant line to the coupling port.  Select the control port (see fig. 23) With “Control port” you specify at which port you are connecting the control line. 1 2 3 STAND-BY ON

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 Note: Configure the coupling port and the redundancy ring ports on different ports.  Activate the function in the “Operation” frame (see fig. 23)  Now connect the redundant line and the control line. The displays in the “Select port” frame mean: – “Port mode”: The port is either active or in stand-by mode. – “Port state”: The port is either connected or not connected. – “IP Address”: The IP address of the partner, if the partner is already operating in the network. The displays in the “Information” frame mean: – “Redundancy guaranteed”: If the main line no longer functions, the redundant line takes over the function of the main line. – “Configuration failure”: The function is incomplete or incorrectly configured. To avoid continuous loops, the Switch sets the port state of the coupling port to “off” if you: – switch off the operation setting or – change the configuration while the connections are in operation at these ports. Note: The following settings are required for the coupling ports (you select the Basic Settings:Port Configuration dialog): – Port: on – Automatic configuration (autonegotiation): on for twisted-pair connections – Manual configuration: 100 Mbit/s FDX, 1 Gbit/s FDX, or 10 Gbit/s FDX, according to the port’s capabilities for glass fiber connections Note: If VLANs are configured, set the coupling and partner coupling ports’ VLAN configuration as follows: – in the dialog Switching:VLAN:Port Port VLAN ID 1 and „Ingress Filtering“ deactivated – in the dialog Switching:VLAN:Static VLAN-Membership U (Untagged)

Release 7.1 12/2011 4.2 Preparing a Ring/Network Coupling 55 Redundancy mode  In the “Redundancy Mode” frame, select: – “Redundant Ring/Network Coupling” or – “Extended Redundancy”. Figure 25: Two-Switch coupling with control line: Selecting the redundancy mode With the “Redundant Ring/Network Coupling” setting, either the main line or the redundant line is active. The lines are never both active at the same time. With the “Extended Redundancy” setting, the main line and the redundant line are simultaneously active if the connection line between the devices in the connected (i.e. remote) network fails (see fig. 12). During the reconfiguration period, package duplications may occur. Therefore, only select this setting if your application detects package duplications.

Coupling UM Redundancy Configuration L2E Release 7.1 12/2011 Figure 26: Extended redundancy Coupling mode The coupling mode indicates the type of the connected network.  In the “Coupling Mode” frame, select: – “Ring coupling” or – “Network Coupling” Figure 27: Two-Switch coupling with control line: Selecting the coupling mode  Select "Ring coupling" if you are connecting to a redundancy ring.  Select "Network Coupling" if you are connecting to a line or tree structure. Delete coupling configuration  The “Delete coupling configuration” button in the dialog allows you to reset all the coupling settings of the device to the state on delivery.

Release 7.1 12/2011 57 5 Spanning Tree Note: The Spanning Tree Protocol is a protocol for MAC bridges. For this reason, the following description uses the term bridge for switch. Local networks are getting bigger and bigger. This applies to both the geographical expansion and the number of network participants. Therefore, it is advantageous to use multiple bridges, for example:  to reduce the network load in sub-areas,  to set up redundant connections and  to overcome distance limitations. However, using multiple bridges with multiple redundant connections between the subnetworks can lead to loops and thus loss of communication across of the network. In order to help avoid this, you can use Spanning Tree. Spanning Tree enables loop-free switching through the systematic deactivation of redundant connections. Redundancy enables the systematic reactivation of individual connections as needed. RSTP is a further development of the Spanning Tree Protocol (STP) and is compatible with it. If a connection or a bridge becomes inoperable, the STP required a maximum of 30 seconds to reconfigure. This is no longer acceptable in time-sensitive applications. RSTP achieves average reconfiguration times of less than a second. When you use RSTP in a ring topology with 10 to 20 devices, you can even achieve reconfiguration times in the order of milliseconds. Note: RSTP reduces a layer 2 network topology with redundant paths into a tree structure (Spanning Tree) that does not contain any more redundant paths. One of the switches takes over the role of the root bridge here. The maximum number of devices permitted in an active branch (from the root bridge to the tip of the branch) is specified by the variable Max Age for the current root bridge. The preset value for Max Age is 20, which can be increased up to 40.

Release 7.1 12/2011 If the device working as the root is inoperable and another device takes over its function, the Max Age setting of the new root bridge determines the maximum number of devices allowed in a branch. Note: The RSTP standard dictates that all the devices within a network work with the (Rapid) Spanning Tree Algorithm. If STP and RSTP are used at the same time, the advantages of faster reconfiguration with RSTP are lost in the network segments that are operated in combination. A device that only supports RSTP works together with MSTP devices by not assigning an MST region to itself, but rather the CST (Common Spanning Tree). Note: By changing the IEEE 802.1D-2004 standard for RSTP, the Standards Commission reduced the maximum value for the “Hello Time” from 10 s to 2 s. When you update the switch software from a release before 5.0 to release 5.0 or higher, the new software release automatically reduces the locally entered “Hello Time” values that are greater than 2 s to 2 s. If the device is not the RSTP root, “Hello Time” values greater than 2 s can remain valid, depending on the software release of the root device.

Release 7.1 12/2011 5.1 The Spanning Tree Protocol 59 5.1 The Spanning Tree Protocol Because RSTP is a further development of the STP, all the following descriptions of the STP also apply to the RSTP. 5.1.1 The tasks of the STP The Spanning Tree Algorithm reduces network topologies built with bridges and containing ring structures due to redundant links to a tree structure. In doing so, STP opens ring structures according to preset rules by deactivating redundant paths. If a path is interrupted because a network component becomes inoperable, STP reactivates the previously deactivated path again. This allows redundant links to increase the availabiliy of communication. STP determines a bridge that represents the STP tree structure‘s base. This bridge is called root bridge. Features of the STP algorithm:  automatic reconfiguration of the tree structure in the case of a bridge becoming inoperable or the interruption of a data path  the tree structure is stabilized up to the maximum network size (up to 39 hops, depending on the setting for Max Age, (see table 13)  stabilization of the topology within a short time period  topology can be specified and reproduced by the administrator  transparency for the terminal devices  low network load relative to the available transmission capacity due to the tree structure created

UM Redundancy Configuration L2E Release 7.1 12/2011 5.1.2 Bridge parameters In the context of Spanning Treee, each bridge and its connections are uniquely described by the following parameters:  Bridge Identifier  Root Path Cost for the bridge ports,  Port Identifier 5.1.3 Bridge Identifier The Bridge Identifier consists of 8 bytes. The 2 highest-value bytes are the priority. The default setting for the priority number is 32,768, but the Management Administrator can change this when configuring the network. The 6 lowest-value bytes of the bridge identifier are the bridge’s MAC address. The MAC address allows each bridge to have unique bridge identifiers. The bridge with the smallest number for the bridge identifier has the highest priority. Figure 28: Bridge Identifier, Example (values in hexadecimal notation) MAC Address Priority LSB MSB 80 80 00 00 63 51 74 00

Release 7.1 12/2011 5.1 The Spanning Tree Protocol 61 5.1.4 Root Path Cost Each path that connects 2 bridges is assigned a cost for the transmission (path cost). The switch determines this value based on the transmission speed (see table 11). It assigns a higher path cost to paths with lower transmission speeds. Alternatively, the Administrator can set the path cost. Like the switch, the Administrator assigns a higher path cost to paths with lower transmission speeds. However, since the Administrator can choose this value freely, he has a tool with which he can give a certain path an advantage among redundant paths. The root path cost is the sum of all individual costs of those paths that a data packet has to traverse from a connected bridge‘s port to the root bridge. Figure 29: Path costs Ethernet (100 Mbit/s) Ethernet (10 Mbit/s) PC Path costs PC = 2 000 000 PC = 200 000 PC = 200 000 Bridge 1 Bridge 2 Bridge 3

UM Redundancy Configuration L2E Release 7.1 12/2011 Data rate Recommended value Recommended range Possible range ≤100 Kbit/s 200,000,000a a. Bridges that conform with IEEE 802.1D 1998 and only support 16-bit values for the path costs should use the value 65,535 (FFFFH) for path costs when they are used in conjunction with bridges that support 32-bit values for the path costs. 20,000,000-200,000,000 1-200,000,000 1 Mbit/s 20,000,000a 2,000,000-200,000,000 1-200,000,000 10 Mbit/s 2,000,000a 200,000-20,000,000 1-200,000,000 100 Mbit/s 200,000a 20,000-2,000,000 1-200,000,000 1 Gbit/s 20,000 2,000-200,000 1-200,000,000 10 Gbit/s 2,000 200-20,000 1-200,000,000 100 Gbit/s 200 20-2,000 1-200,000,000 1 TBit/s 20 2-200 1-200,000,000 10 TBit/s 2 1-20 1-200,000,000 Table 11: Recommended path costs for RSTP based on the data rate.

Release 7.1 12/2011 5.1 The Spanning Tree Protocol 63 5.1.5 Port Identifier The port identifier consists of 2 bytes. One part, the lower-value byte, contains the physical port number. This provides a unique identifier for the port of this bridge. The second, higher-value part is the port priority, which is specified by the Administrator (default value: 128). It also applies here that the port with the smallest number for the port identifier has the highest priority. Figure 30: Port Identifier Priority Port number MSB LSB

Structure UM Redundancy Configuration L2E Release 7.1 12/2011 5.2 Rules for Creating the Tree Structure 5.2.1 Bridge information To determine the tree structure, the bridges need more detailed information about the other bridges located in the network. To obtain this information, each bridge sends a BPDU (Bridge Protocol Data Unit) to the other bridges. The contents of a BPDU include  bridge identifier,  root path costs and  port identifier (see IEEE 802.1D). 5.2.2 Setting up the tree structure  The bridge with the smallest number for the bridge identifier is called the root bridge. It is (or will become) the root of the tree structure.  The structure of the tree depends on the root path costs. Spanning Tree selects the structure so that the path costs between each individual bridge and the root bridge become as small as possible.

Release 7.1 12/2011 5.2 Rules for Creating the Tree Structure 65  If there are multiple paths with the same root path costs, the bridge further away from the root decides which port it blocks. For this purpose, it uses the bridge identifiers of the bridge closer to the root. The bridge blocks the port that leads to the bridge with the numerically higher ID (a numerically higher ID is the logically worse one). If 2 bridges have the same priority, the bridge with the numerically larger MAC address has the numerically higher ID, which is logically the worse one.  If multiple paths with the same root path costs lead from one bridge to the same bridge, the bridge further removed from the root uses the port identifier of the other bridge as the last criterion (see fig. 30). In the process, the bridge blocks the port that leads to the port with the numerically higher ID (a numerically higher ID is the logically worse one). If 2 ports have the same priority, the port with the higher port number has the numerically higher ID, which is logically the worse one.

Structure UM Redundancy Configuration L2E Release 7.1 12/2011 Figure 31: Flow diagram for specifying the root path Equal path costs? Determine root path no yes Equal priority in bridge identification? Equal port priority? yes yes Path with lowest path costs = root path Path with highest port priority = root path Path with highest priority in bridge identification = root path no no Path with lowest port number = root path Root path determined

Release 7.1 12/2011 5.3 Example of determining the root path 67 5.3 Example of determining the root path You can use the network plan (see fig. 32) to follow the flow chart (see fig. 31) for determining the root path. The administrator has specified another priority in the bridge identification for each bridge. The bridge with the smallest numerical value for the bridge identification takes on the role of the root bridge, in this case, bridge 1. In the example all the sub-paths have the same path costs. The protocol blocks the path between bridge 2 and bridge 3 as a connection from bridge 3 via bridge 2 to the root bridge would result in higher path costs. The path from bridge 6 to the root bridge is interesting:  The path via bridge 5 and bridge 3 creates the same root path costs as the path via bridge 4 and bridge 2.  The bridges select the path via bridge 4 because the value 28,672 for the priority in the bridge identifier is smaller than value 32,768.  There are also 2 paths between bridge 6 and bridge 4. The port identifier is decisive here.

path UM Redundancy Configuration L2E Release 7.1 12/2011 Figure 32: Example of determining the root path Root path Port 2 Interrupted path P-BID Priority of the bridge identifikation (BID) = BID without MAC Address Bridge 1 P-BID = 16 384 Bridge 2 P-BID = 20 480 Bridge 3 P-BID = 24 576 Bridge 5 P-BID = 32 768 Bridge 6 P-BID = 36 864 Bridge 4 Port 1 Port 3 Bridge 7 P-BID = 40 960 P-BID = 28 672

Release 7.1 12/2011 5.4 Example of manipulating the root path 69 5.4 Example of manipulating the root path You can use the network plan (see fig. 32) to follow the flow chart (see fig. 31) for determining the root path. The Administrator has performed the following: – Left the default value of 32,768 (8000H) for every bridge apart from bridge 1, and – assigned to bridge 1 the value 16,384 (4000H), thus making it the root bridge. In the example, all the sub-paths have the same path costs. The protocol blocks the path between bridge 2 and bridge 3 as a connection from bridge 3 via bridge 2 to the root bridge would mean higher path costs. The path from bridge 6 to the root bridge is interesting:  The path via bridge 5 and bridge 3 creates the same root path costs as the path via bridge 4 and bridge 2.  STP selects the path using the bridge that has the lowest MAC address in the bridge identification (bridge 4 in the illustration).  There are also 2 paths between bridge 6 and bridge 4. The port identifier is decisive here. Note: Because the Administrator does not change the default values for the priorities of the bridges in the bridge identifier, apart from the value for the root bridge, the MAC address in the bridge identifier alone determines which bridge becomes the new root bridge if the current root bridge goes down.

path UM Redundancy Configuration L2E Release 7.1 12/2011 Figure 33: Example of manipulating the root path Port 2 Bridge 1 P-BID = 16 384 Bridge 2 P-BID = 32 768 Bridge 3 P-BID = 32 768 Bridge 5 P-BID = 32 768 Bridge 6 P-BID = 32 768 Bridge 7 P-BID = 32 768 P-BID = 32 768 Bridge 4 Port 1 Port 3 Root path Interrupted path P-BID Priority of the bridge identifikation (BID) = BID without MAC Address

Release 7.1 12/2011 5.5 Example of manipulating the tree structure 71 5.5 Example of manipulating the tree structure The Management Administrator soon discovers that this configuration with bridge 1 as the root bridge (see on page 67 “Example of determining the root path”) is invalid. On the paths from bridge 1 to bridge 2 and bridge 1 to bridge 3, the control packets which the root bridge sends to all other bridges add up. If the Management Administrator configures bridge 2 as the root bridge, the burden of the control packets on the subnetworks is distributed much more evenly. The result is the configuration shown here (see fig. 34). The path costs for most of the bridges to the root bridge have decreased. Figure 34: Example of manipulating the tree structure Bridge 5 P-BID = 28 672 Bridge 7 P-BID = 40 960 P-BID = 20 480 Bridge 3 P-BID = 24 576 Bridge 1 P-BID = 32 768 Bridge 2 P-BID = 16 384 P-BID = 36 864 Bridge 6 Port 3 Bridge 4 Port 1 Port 2 Root path Interrupted path P-BID Priority of the bridge identifikation (BID) = BID without MAC Address

Protocol UM Redundancy Configuration L2E Release 7.1 12/2011 5.6 The Rapid Spanning Tree Protocol The RSTP uses the same algorithm for determining the tree structure as STP. RSTP merely changes parameters, and adds new parameters and mechanisms that speed up the reconfiguration if a link or bridge becomes inoperable. The ports play a significant role in this context. 5.6.1 Port roles RSTP assigns each bridge port one of the following roles (see fig. 35):  Root port This is the port on which a bridge receives data packets with the lowest path costs from the root bridge. If there is more than 1 port with the same low path costs, the bridge identifier determines which port is the root port. If there is more than 1 port with the same low path costs connected to the same bridge, the port identifier determines which port is the root port (see fig. 31). The root bridge itself does not have a root port.  Designated port The bridge in a network segment that has the lowest root path costs is the designated bridge. If more than 1 bridge has the same root path costs, the bridge with the smallest value bridge identifier becomes the designated bridge. The port on this bridge that connects it to a network segment leading to the root bridge, is the designated port.

Release 7.1 12/2011 5.6 The Rapid Spanning Tree Protocol 73  Edge port Every network segment with no additional RSTP bridges is connected with exactly one designated port. In this case, this designated port is also an edge port. The distinction of an edge port is the fact that it does not receive any RST BPDUs (Rapid Spanning Tree Bridge Protocol Data Units).  Alternate port This is a blocked port that takes over the task of the bridge port if the connection to the root bridge is lost. The alternate port provides a backup connection to the root bridge.  Backup port This is a blocked port that serves as a backup in case the connection to the designated port of this network segment (without any RSTP bridges) is lost  Disabled port This is a port that does not participate in the Spanning Tree Operation, i.e., the port is switched off or does not have any connection.

Protocol UM Redundancy Configuration L2E Release 7.1 12/2011 Figure 35: Port role assignment 5.6.2 Port states Depending on the tree structure and the state of the selected connection paths, the RSTP assigns the ports their states. P-BID Priority of the bridge identifikation (BID) = BID without MAC Address Root path Interrupted path Root port Designated port Alternate port Backup port Edge port Port 1 Port 2 Bridge 2 P-BID = 20 480 Bridge 3 P-BID = 24 576 Bridge 5 P-BID = 32 768 Bridge 1 P-BID = 16 384 Bridge 7 P-BID = 40 960 P-BID = 28 672 Bridge 4

Release 7.1 12/2011 5.6 The Rapid Spanning Tree Protocol 75 Meaning of the RSTP port states:  Disabled: Port does not belong to the active topology  Discarding: No address learning in FDB, no data traffic except for BPDUs  Learning: Address learning active (FDB) and no data traffic except for BPDUs  Forwarding: Address learning is active (FDB), sending and receipt of all frame types (not only BPDUs) 5.6.3 Spanning Tree Priority Vector To assign roles to the ports, the RSTP bridges exchange configuration information with each other. This information is known as the Spanning Tree Priority Vector. It is part of the RSTP BPDUs and contains the following information:  Bridge identification of the root bridge  Root path costs of the sending bridge  Bridge identification of the sending bridge  Port identifiers of the ports through which the message was sent  Port identifiers of the ports through which the message was received STP port state Administrative bridge port state MAC operational RSTP Port state Active topology (port role) DISABLED Disabled FALSE Discardinga a. The dot1d-MIB displays “Disabled” Excluded (disabled) DISABLED Enabled FALSE Discardinga Excluded (disabled) BLOCKING Enabled TRUE Discardingb b. The dot1d-MIB displays “Blocked” Excluded (alternate, backup) LISTENING Enabled TRUE Discardingb Included (root, designated) LEARNING Enabled TRUE Learning Included (root, designated) FORWARDING Enabled TRUE Forwarding Included (root, designated) Table 12: Relationship between port state values for STP and RSTP.

Protocol UM Redundancy Configuration L2E Release 7.1 12/2011 Based on this information, the bridges participating in RSTP are able to determine port roles themselves and define the port states of their own ports. 5.6.4 Fast reconfiguration Why can RSTP react faster than STP to an interruption of the root path?  Introduction of edge-ports: During a reconfiguration, RSTP switches an edge port into the transmission mode after three seconds and then waits for the “Hello Time” (see table 13) to elapse, to be sure that no bridge sending BPDUs is connected. When the user determines that a terminal device is connected at this port and will remain connected, he can switch off RSTP at this port. Thus no waiting times occur at this port in the case of a reconfiguration.  Introduction of alternate ports: As the port roles are already distributed in normal operation, a bridge can immediately switch from the root port to the alternative port after the connection to the root bridge is lost.  Communication with neighboring bridges (point-to-point connections): Decentralized, direct communication between neighboring bridges enables reaction without wait periods to status changes in the spanning tree topology.  Address table: With STP, the age of the entries in the FDB determines the updating of communication. RSTP immediately deletes the entries in those ports affected by a reconfiguration.  Reaction to events: Without having to adhere to any time specifications, RSTP immediately reacts to events such as connection interruptions, connection reinstatements, etc.

Release 7.1 12/2011 5.6 The Rapid Spanning Tree Protocol 77 Note: The downside of this fast reconfiguration is the possibility that data packages could be duplicated and/or arrive at the recipient in the wrong order during the reconfiguration phase of the RSTP topology. If this is unacceptable for your application, use the slower Spanning Tree Protocol or select one of the other, faster redundancy procedures described in this manual. 5.6.5 Configuring the Rapid Spanning Tree  Set up the network to meet your demands. Note: Before you connect the redundant lines, you must complete the configuration of the RSTP. You thus avoid loops during the configuration phase.  For devices with DIP switches, you switch these to “deactivated” (both to ON), so that the software configuration is not restricted.  Select the Redundancy:Rapid Spanning Tree:Global dialog.

Protocol UM Redundancy Configuration L2E Release 7.1 12/2011  Switch on RSTP on each device Figure 36: Operation on/off

Release 7.1 12/2011 5.6 The Rapid Spanning Tree Protocol 79  Define the desired switch as the root bridge by assigning it the lowest priority in the bridge information among all the bridges in the network, in the “Protocol Configuration/Information” frame. Note that only multiples of 4,096 can be entered for this value (see table 13). In the “Root Information” frame, the dialog shows this device as the root. A root switch has no root port and a root cost of 0.  If necessary, change the default priority value of 32,768 in other bridges in the network in the same way to the value you want (multiples of 4,096). For each of these bridges, check the display in the “Root Information” frame: – Root-ID: Displays the root bridge’s bridge identifier – Root Port: Displays the port leading to the root bridge – Root Cost: Displays the root cost to the root bridge in the “Protocol Configuration/Information” frame: – Priority: Displays the priority in the bridge identifier for this bridge – MAC Address: Displays the MAC address of this Switch – Topology Changes: Displays the number of changes since the start of RSTP – Time since last change: Displays the time that has elapsed since the last network reconfiguration  If necessary, change the values for “Hello Time”, “Forward Delay” and “Max. Age” on the rootbridge. The root bridge then transfers this data to the other bridges. The dialog displays the data received from the root bridge in the left column. In the right column you enter the values which shall apply when this bridge becomes the root bridge. For the configuration, take note of table 13.

Protocol UM Redundancy Configuration L2E Release 7.1 12/2011 Figure 37: Assigning Hello Time, Forward Delay and Max. Age The times entered in the RSTP dialog are in units of 1 s Example: a Hello Time of 2 corresponds to 2 seconds.  Now connect the redundant lines.

Release 7.1 12/2011 5.6 The Rapid Spanning Tree Protocol 81 Parameter Meaning Possible Values Default Setting Priority The priority and the MAC address go together to make up the bridge identification. 0 < n*4,096 (1000H) < 61,440 (F000H) 32,768 (8000H) Hello Time Sets the Hello Time. The local Hello Time is the time in seconds between the sending of two configuration messages (Hello packets). If the local device has the root function, the other devices in the entire network take over this value. Otherwise the local device uses the value of the root bridge in the “Root” column on the right. 1 - 2 2 Forward Delay Sets the Forward Delay parameter. In the previous STP protocol, the Forward Delay parameter was used to delay the status change between the statuses disabled, discarding, learning, forwarding. Since the introduction of RSTP, this parameter has a subordinate role, because the RSTP bridges negotiate the status change without any specified delay. If the local device is the root, the other devices in the entire network take over this value. Otherwise the local device uses the value of the root bridge in the “Root” column on the right. 4 - 30 s See the note following this table. 15 s Max Age Sets the Max Age parameter. In the previous STP protocol, the Max Age parameter was used to specify the validity of STP BPDUs in seconds. For RSTP, Max Age signifies the maximum permissible branch length (number of devices to the root bridge). If the local device is the root, the other devices in the entire network take over this value. Otherwise the local device uses the value of the root bridge in the “Root” column on the right. 6 - 40 s See the note following this table. 20 s Table 13: Global RSTP settings

Protocol UM Redundancy Configuration L2E Release 7.1 12/2011 Figure 38: Definition of diameter and age The network diameter is the number of connections between the two devices furthest away from the root bridge. = Root 1 Diameter = 7 Age = 5 2 3 4 5 1 2 3 4 5 6 7 Age = 4 1 2 3 4

Release 7.1 12/2011 5.6 The Rapid Spanning Tree Protocol 83 Note: The parameters – Forward Delay and – Max Age have a relationship to each other: Forward Delay ≥ (Max Age/2) + 1 If you enter values that contradict this relationship, the device then replaces these values with a default value or with the last valid values.  When necessary, change and verify the settings and displays that relate to each individual port (dialog: Rapid Spanning Tree:Port). Figure 39: Configuring RSTP for each port Note: Deactivate the Spanning Tree Protocol on the ports connected to a redundant ring, because Spanning Tree and Ring Redundancy work with different reaction times.

Protocol UM Redundancy Configuration L2E Release 7.1 12/2011 If you are using the device in a Multiple Spanning Tree (MSTP) environment, the device only participates in the Common Spanning Tree (CST) instance. This chapter of the manual also uses the term Global MST instance to describe this general case. Parameter Meaning Possible Values Default Setting STP active Here you can switch Spanning Tree on or off for this port. If Spanning Tree is activated globally and switched off at one port, this port does not send STP-BPDUs and drops any STP-BPDUs received. Note: If you want to use other layer 2 redundancy protocols such as HIPER-Ring or Ring/Network coupling in parallel with Spanning Tree, make sure you switch off the ports participating in these protocols in this dialog for Spanning Tree. Otherwise the redundancy may not operate as intended or loops can result. On, Off On Port status (read only) Displays the STP port status with regard to the global MSTI (IST). discarding, learning, forwarding, disabled, manualForwarding, notParticipate - Port priority Here you enter the port priority (the four highest bits of the port ID) with regard to the global MSTI (IST) as a decimal number of the highest byte of the port ID. 16 ≤ n·16 ≤ 240 128 Port path costs Enter the path costs with regard to the global MSTI (IST) to indicate preference for redundant paths. If the value is 0, the switch automatically calculates the path costs for the global MSTI (IST) depending on the transmission rate. 0 - 200,000,000 0 (automatically) Table 14: Port-related RSTP settings and displays

Release 7.1 12/2011 5.6 The Rapid Spanning Tree Protocol 85 Admin Edge Port Only activate this setting when a terminal device is connected to the port (administrative: default setting). Then the port immediately has the forwarding status after a link is set up, without first going through the STP statuses. If the port still receives an STP-BPDU, the device blocks the port and clarifies its STP port role. In the process, the port can switch to a different status, e.g. forwarding, discarding, learning. Deactivate the setting when the port is connected to a bridge. After a link is set up, the port then goes through the STP statuses first before taking on the forwarding status, if applicable. This setting applies to all MSTIs. active (box selected), inactive (box empty) inactive Oper Edge Port (read only) The device sets the “Oper Edge Port” condition to true if it has not received any STP-BPDUs, i.e. a terminal device is connected. It sets the condition to false if it has received STP-BPDUs, i.e. a bridge is connected. This condition applies to all MSTIs. true, false - Auto Edge Port The device only considers the Auto Edge Port setting when the Admin Edge Port parameter is deactivated. If Auto Edge Port is active, after a link is set up the device sets the port to the forwarding status after 1.5 · Hello Time (in the default setting 3 s). If Auto Edge Port is deactivated, the device waits for the Max Age instead (in the default setting 20 s). This setting applies to all MSTIs. active (box selected), inactive (box empty) active Parameter Meaning Possible Values Default Setting Table 14: Port-related RSTP settings and displays

Protocol UM Redundancy Configuration L2E Release 7.1 12/2011 – a These columns show you more detailed information than that available up to now: For designated ports, the device displays the information for the STP- BPDU last received by the port. This helps with the diagnosis of possible STP problems in the network. For the port roles alternative, back-up, master and root, in the stationary condition (static topology), this information is identically to the designated information. If a port has no link, or if it has not received any STP-BDPUs for the current MSTI, the device displays the values that the port would send as a designated port. Oper Point-to- Point (read only) The device sets the “Oper point-to- point” condition to true if this port has a full duplex condition to an STP device. Otherwise it sets the condition to false (e.g. if a hub is connected). The point-to-point connection makes a direct connection between 2 RSTP devices. The direct, decentralized communication between the two bridges results in a short reconfiguration time. This condition applies to all MSTIs. true, false The device determines this condition from the duplex mode: FDX: true HDX: false Received bridge ID (read only) Displays the remote bridge ID from which this port last received an STP- BPDU.a Bridge identification (format ppppp / mm mm mm mm mm mm) - Received path costs (read only) Displays the path costs of the remote bridge from its root port to the CIST root bridge.a 0-200,000,000 - Received port ID (read only) Displays the port ID at the remote bridge from which this port last received an STP-BPDU.a Port ID, format pn nn, with p: port priority / 16, nnn: port No., (both hexadecimal) - Parameter Meaning Possible Values Default Setting Table 14: Port-related RSTP settings and displays

Release 7.1 12/2011 5.7 Combining RSTP and MRP 87 5.7 Combining RSTP and MRP In the MRP compatibility mode, the device allows you to combine RSTP with MRP. With the combination of RSTP and MRP, the fast switching times of MRP are maintained. The RSTP diameter (see fig. 38) depends on the “Max Age”. It applies to the devices outside the MRP-Ring. Note: The combination of RSTP and MRP presumes that both the root bridge and the backup root bridge are located within the MRP-Ring. Figure 40: Combination of RSTP and MRP 1: MRP-Ring 2: RSTP-Ring RM: Ring Manager RM 1 2

UM Redundancy Configuration L2E Release 7.1 12/2011 To combine RSTP with MRP, you perform the following steps in sequence:  Configure MRP on all devices in the MRP-Ring.  Close the redundant line in the MRP-Ring.  Activate RSTP at the RSTP ports and also at the MRP-Ring ports.  Configure the RSTP root bridge and the RSTP backup root bridge in the MRP-Ring: – Set their priority. – If you exceed the RSTP diameter specified by the preset value of Max Age = 20, modify Max Age and Forward Delay accordingly.  Switch on RSTP globally.  Switch on the MRP compatibility mode.  After configuring all the participating devices, connect the redundant RSTP connection.

Release 7.1 12/2011 5.7 Combining RSTP and MRP 89 5.7.1 Application example for the combination of RSTP and MRP The figure (see fig. 41) shows an example for the combination of RSTP and MRP. Parameters S1 S2 S3 S4 S5 S6 MRP settings Ring redundancy: MRP version MRP MRP MRP MRP Ring port 1 1.1 1.1 1.1 1.1 Ring port 2 1.2 1.2 1.2 1.2 Port from MRP-Ring to the RSTP network 1.3 1.3 - - - - Redundancy Manager mode On Off – – Off Off MRP operation On On Off Off On On RSTP settings For each RSTP port: STP State Enable On On On On On On Protocol Configuration: priority (S2

UM Redundancy Configuration L2E Release 7.1 12/2011 Prerequisites for further configuration:  You have configured the MRP settings for the devices in accordance with the above table.  The redundant line in the MRP-Ring is closed. Figure 41: Application example for the combination of RSTP and MRP 1: MRP-Ring, 2: RSTP-Ring, 3: Redundant RSTP connection RM: Ring Manager S2 is RSTP Root Bridge S1 is RSTP Backup Root Bridge  Activate RSTP at the ports, using S1 as an example (see table 15). enable Switch to the privileged EXEC mode. configure Switch to the Configuration mode. interface 1/1 Switch to the Interface Configuration mode of interface 1/1. spanning-tree port mode Activate RSTP on the port. exit Switch to the Configuration mode. interface 1/2 Switch to the interface configuration mode for port 1.2. spanning-tree port mode Activate RSTP on the port. RM S1 S3 S2 S4 3 1.1 1.1 1.2 1.3 1.3 1.2 1.1 1.2 1.1 1.2 1 2 S5 S6 1.1 1.1 1.2 1.2

Release 7.1 12/2011 5.7 Combining RSTP and MRP 91  Configure the global settings, using S1 as an example: – the RSTP priority – global operation – the MRP compatibility mode  Configure the other switches S2 though S6 with their respective values (see table 15).  Connect the redundant RSTP connection. exit Switch to the Configuration mode. interface 1/3 Switch to the interface configuration mode for port 1.3. spanning-tree port mode Activate RSTP on the port. exit Switch to the Configuration mode. spanning-tree mst priority 0 4096 Set the RSTP priority for the MST instance 0 to the value 4,096. the MST instance 0 is the default instance. spanning-tree Activate RSTP operation globally. spanning-tree stp-mrp-mode Activate MRP compatibility.

Release 7.1 12/2011 A Readers’ Comments What is your opinion of this manual? We are always striving to provide as comprehensive a description of our product as possible, as well as important information that will ensure trouble-free operation. Your comments and suggestions help us to further improve the quality of our documentation. Your assessment of this manual: Did you discover any errors in this manual? If so, on what page? Very good Good Satisfactory Mediocre Poor Precise description O O O O O Readability O O O O O Understandability O O O O O Examples O O O O O Structure O O O O O Completeness O O O O O Graphics O O O O O Drawings O O O O O Tables O O O O O

Release 7.1 12/2011 93 Suggestions for improvement and additional information: General comments: Sender: Dear User, Please fill out and return this page  as a fax to the number +49 (0)7127 14-1600 or  by post to Hirschmann Automation and Control GmbH Department 01RD-NT Stuttgarter Str. 45-51 72654 Neckartenzlingen Company / Department: Name / Telephone no.: Street: Zip code / City: e-mail: Date / Signature:

Release 7.1 12/2011 B Index A Advanced Mode 21 Age 82 Alternate port 73, 73 B Backup port 73 Bridge Identifier 60, 60 C Configuration error 20, 24 Configuring the HIPER-Ring 16 D DIP-switch 16 Designated bridge 72 Designated port 72, 72 Diameter 82 Disabled port 73 E Edge port 73, 73, 73 F FAQ 97 Forward Delay 81 H HIPER-Ring 5, 9, 11 Hello Time 81 HiVision 6 I Industry Protocols 5 L Loops 44, 46, 52, 54 M MRP 5 Max Age 81 Message URL http://www.hicomcenter.com 98 P PROFINET IO 5 Path Cost 64 Port priority (Spanning Tree) 63 Port-State 74 R RST BPDU 73, 75 RSTP 9 Rapid Spanning Tree 9 Redundancy 5 Redundancy Manager 14 Redundancy existing 20, 24 Redundancy functions 9 Redundant 13 Redundant Coupling 9, 11 Redundant connections 57 Redundant coupling 9 Ring 13 Ring Manager 14 Ring Redundancy 10, 10, 10 Ring coupling 5 Ring structure 14 Ring/Network coupling 9 Root Path Cost 60 Root port 72, 72 S Symbol 7 T Technical Questions 97 Training Courses 97 V VLAN (settings for HIPER-Ring) 19

Release 7.1 12/2011 97 C Further Support  Technical Questions For technical questions, please contact any Hirschmann dealer in your area or Hirschmann directly. You will find the addresses of our partners on the Internet at http://www.beldensolutions.com Contact our support at https://hirschmann-support.belden.eu.com You can contact us in the EMEA region at  Tel.: +49 (0)1805 14-1538  E-mail: [email protected] in the America region at  Tel.: +1 (717) 217-2270  E-mail: [email protected] in the Asia-Pacific region at  Tel.: +65 68549860  E-mail: [email protected]  Hirschmann Competence Center The Hirschmann Competence Center is ahead of its competitors:  Consulting incorporates copmprehensive technical advice, from system evaluation through network planning to project planning.  Training offers you an introduction to the basics, product briefing and user training with certification. The current training courses to technology and products can be found at http://www.hicomcenter.com  Support ranges from the first installation through the standby service to maintenance concepts.

Release 7.1 12/2011 With the Hirschmann Competence Center, you have decided against making any compromises. Our client-customized package leaves you free to choose the service components you want to use. Internet: http://www.hicomcenter.com