Redundancy Configuration: MICE Switch Power (MSP)
Contents
1. Ring Port 1 Ring Port 2 Operation nctconnected Operation notConnected Configuration Ring Manager Con off Advanced Mode Ring Recovery C 500ms 200ms VLAN ID lo Information m Set Reload Delete ring configuration Help Figure 8 Defining the ring ports In the Command Line Interface you first define an additional parameter the MRP domain ID Configure all the ring participants with the same MRP domain ID The MRP domain ID is a sequence of 16 number blocks 8 bit values When configuring with the graphical user interface the device uses the default value 255 255 255 255 255 255 255 255 255 255 255 255 ZOD ZOD Zoo ZOU mrp domain add default domain Creates anew MRP domain with the default domain ID mrp domain modify port Defines port 1 1 as ring port 1 primary primary 1 1 mro domain mod ry port Defines port 1 2 as ring port 2 secondary secondary 1 2 UM RedundConfig MSP Release 2 0 02 2013 21 Media Redundancy Protocol MRP 2 5 Example Configuration L Activate the ring manager For the other devices in the ring leave the setting as Off Figure 9 Activating the ring manager mrp domain modify mode Defines the device as the ring manager Do not manager activate the ring manager on any other device UM RedundConfig MSP 22 Release 2 0 02 2013 Media Redundancy Protocol MRP 2 5 Example Configuration L Select the checkbox in the Advanced Mode field Figure 10 Activat2. 0 02 2013 Media Redundancy Protocol MRP 2 Media Redundancy Protocol MRP Since May 2008 the Media Redundancy Protocol MRP has been a standardized solution for ring redundancy in the industrial environment MRP is compatible with redundant ring coupling supports VLANs and is distinguished by very short reconfiguration times An MRP Ring consists of up to 50 devices that support the MRP protocol according to IEC 62439 If you only use Hirschmann devices up to 100 devices are possible in the MRP Ring UM RedundConfig MSP Release 2 0 02 2013 13 Media Redundancy Protocol MRP 2 1 Network Structure 2 1 Network Structure 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 gt lt Figure 4 Figure 5 14 Be ee ee En ee Line structure Redundant ring structure RM Ring Manager main line redundant line UM RedundConfig MSP Release 2 0 02 2013 Media Redundancy Protocol MRP 2 2 Reconfiguration time 2 2 Reconfiguration time If a line section fails the ring manager changes the MRP Ring bac
3. 2 0 02 2013 55 Spanning Tree 3 5 Configuring the device Note If possible do not change the value in the Hello Time field Check the following values in the other devices Bridge ID bridge priority and MAC address of the corresponding device and the root bridge Number of the device port that leads to the root bridge Path cost from the root port of the device to the root bridge Operation Protocol Version fon Off IRSTP Protocol Configuration Information Bridge Root Topology Bridge ID s2768 00 80 64 ca ff ee 4096 00 80 63 51 7400 Bridge is Root E Priority 32768 4096 Root Port fi 5 Hello Time s F 2 Root Path Cost 240000 Forward Delay s fi 5 fi 5 Topology Change Count fi Max Age 20 20 Time Since Topology Change fo day s 0 01 54 Tx Hold Count fi 0 BPDU Guard Set Reload Help Figure 30 Check values show spanning tree global Displays the parameters for checking UM RedundConfig MSP 56 Release 2 0 02 2013 Spanning Tree 3 6 Guards 3 6 Guards The device allows you to activate various protection functions guards on the device ports The following protection functions help protect your network from incorrect configurations loops and attacks with STP BPDUs BPDU Guard for manually defined terminal device ports edge ports You activate this protection function globally in the device Root BPDU a Terminal device ports do not normally receive a
4. 6 1 Activating the BPDU Guard 60 3 6 2 Activating Root Guard TCN Guard Loop Guard 63 A Readers Comments 65 B Index 67 C Further Support 69 UM RedundConfig MSP 4 Release 2 0 02 2013 About this Manual About this Manual 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 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 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 Redundancy Configuration user manual document contains the information you require to select the suitable redundancy procedure and configure it The HiView user manual contains information for using the HiView GUI application This application allows you to use the graphical user interface of Hirschmann devices with management independently of other applications such as a browser UM RedundConfig MSP Release 2 0 02 2013 5 About this Manual The Industrial HiVision Network Manag
5. 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 PC 200000 PC 200000000 PC Path costs Ethernet 100 Mbit s Ethernet 10 Mbit s Figure 17 Path costs Data rate Recommended value Recommended range Possible range lt 100 Kbit s 200 000 000 20 000 000 200 000 000 1 200 000 000 1 Mbit s 20 000 000 2 000 000 200 000 000 1 200 000 000 10 Mbit s 2 000 000 200 000 20 000 000 1 200 000 000 100 Mbit s 200 000 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 3 Recommended path costs for RSTP based on the data rate UM RedundConfig MSP Release 2 0 02 2013 33 Spanning Tree 3 1 Basics 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 3 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
6. h HIRSCHMANN ABELDEN BRAND User Manual Redundancy Configuration MICE Switch Power MSP UM RedundConfig MSP Technical Support Release 2 0 02 2013 https hirschmann support belden eu com The naming of copyrighted trademarks in this manual even when not specially indicated should 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 2013 Hirschmann Automation and Control GmbH Manuals and software are protected by copyright Allrights 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 DVD 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 ass
7. 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 L 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 UM RedundConfig MSP 18 Release 2 0 02 2013 Media Redundancy Protocol MRP 2 5 Example Configuration Porttype Bit rate Autonegotiation Port setting Duplex automatic configuration 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 Table 2 Port settings for ring ports Note You configure optical ports without support for autonegotiation automatic configuration with 100 Mbit s full duplex FDX or 1000 Mbit s full duplex FDX UM RedundConfig MSP Release 2 0 02 2013 19 Media Redundancy Protocol MRP 2 5 Example Configuration 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 configu
8. value The root bridge receives the numerically lowest bridge priority of all the devices in the network Protocol Version Operation On off Rstr Protocol Configuration Information Bridge Root Topology Bridge ID 32768 008064catfee 20480 0080630T1db0 Bridge is Root B Priority Root Port hs o HeloTimets 2 BR Root Path Cost Fi Forward Delay s hs fo oo Topology Change Count bo Max Age Fr 6 Time Since Topology Change 0 day s 0 35 34 Tx Hold Count fi 0 BPDU Guard iv Set Reload Help Figure 27 Defining the bridge priority Click on Set to save the changes spanning tree mst priority 0 Defines the bridge priority of the device lt 0 01440 in AU9ter Schritren gt UM RedundConfig MSP Release 2 0 02 2013 53 Spanning Tree 3 5 Configuring the device After saving the dialog shows the following information The Bridge is Root checkbox is selected The Root Port field shows the value 0 0 The Root Path Cost field shows the value 0 Operation gt Protocol Yersion Con Gon RB en ran Information Bridge Root Topology Bridge ID 4096 00 8064cattee 4096 008064catfee Bridge is Root Vv Priority 4096 hos o Root Pot bo HeloTimeis Bo E Rost Path Cost oO Forward Delay s VE fs Topology Change Count ia Max Age Fu po Time Since Topology Change 0 day s 0 00 53 Tx Hold Cout ho BPDU Guard E Set Reload Help Figure 28 Dev
9. 1 Basics 3 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 3 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 MSB LSB oj oj of en Ss n o u jx qq_ lt cw Priority MAC Address Figure 16 Bridge Identifier Example values in hexadecimal notation UM RedundConfig MSP 32 Release 2 0 02 2013 Spanning Tree 3 1 Basics 3 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 3 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
10. 80 64 ci d sablec Stp Port Port Port Port Received Received Received Admin Auto active State Role Pathcost Priority Bridge ID Port ID Path Cost Edge Port Edge Port 1 disabled disabled 2768 00 80 64 ci 00 00 E u Iv 2 disabled disabled 2768 00 80 64 00 00 I v v 00 80 64 ci Mant JalF wc 00 80 64 ci QKK d disablec d 700 5064 ci sablec i 00 60 64 ci i d OO 60 64 ci 7005064 ci 7 00 80 64 ci i J OO 80 64 ci J sablec d 4 sablec MIIIRN PROT ROT RoR R r 4 aolaolalalalalalala la a I I In 4 Aiminmininininialn co ao oo I aa 5a a a0 d d disablec d cd sablec III TTS Help Set Reload Figure 32 Port dialog CIST tab Click on Set to save the changes Switches to the interface mode Designates the port as a terminal device port edge port Displays the parameters for checking Leaves the interface mode interface x y spanning tree edge port show spanning tree port x y exit UM RedundConfig MSP Release 2 0 02 2013 61 Spanning Tree 3 6 Guards If an edge port receives an STP BPDU the device behaves as follows The device deactivates this port In the Basic Configuration Port Configuration dialog the checkbox in the Port on column is
11. P is a further development of the Spanning Tree Protocol STP and is compatible with it Ifa 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 UM RedundConfig MSP Release 2 0 02 2013 29 Spanning Tree 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 on
12. Set Reload Help Figure 15 Changing the VLAN ID If the MRP Ring is not assigned to a VLAN link in this example leave the VLAN ID as 0 In the Switching VLAN Static dialog define the VLAN membership as U untagged for the ring ports in VLAN 1 If the MRP Ring is assigned to a VLAN enter a VLAN ID gt 0 Inthe Switching VLAN Static dialog define the VLAN membership as T tagged for the ring ports in the selected VLAN mrp domain modify vlan Assigns the VLAN ID lt 0 4042 gt UM RedundConfig MSP 28 Release 2 0 02 2013 Spanning Tree 3 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 RST
13. akes over its function Configuration error Ring port link error Error in the cabling of the ring ports The following messages are possible if the device is operating as a ring manager Configuration error Packet of other ring manager received Another device exists in the ring that is operating as the ring manager Activate the Ring Manager function if there is exactly one device in the ring Configuration error Connection in ring is connected to incorrect port A line in the ring is connected with a different port instead of with a ring port The device only receives test data packets on 1 ring port Operation on off Ring Port 1 Ring Port 2 Port fia v Port 12 v Operation InstConnected Operation InstConnected Configuration Ring Manager on off Advanced Mode Iv Ring Recovery C 500ms 200ms LAN ID lo Information Configuration error error on ringport link Set Reload Delete ring configuration Help Figure 14 Messages in the Information field UM RedundConfig MSP Release 2 0 02 2013 27 Media Redundancy Protocol MRP 2 5 Example Configuration If applicable integrate the MRP ring into a VLAN Change the value in the VLAN field On off Ring Port 1 Ring Port 2 Port 1 1 Port 12 yf Operation blocked Operation forwarding Configuration Ring Manager On C off Advanced Mode v Ring Recover y C 500ms 200ms VLANID Information
14. 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 MSB LSB 7 Priority Port number Figure 18 Port Identifier UM RedundConfig MSP 34 Release 2 0 02 2013 Spanning Tree 3 1 Basics 3 1 6 Max Age and Diameter The Max Age and Diameter values largely determine the maximum expansion of a Spanning Tree network Diameter The number of connections between the devices in the network that are furthest removed from each other is known as the network diameter Figure 19 Definition of diameter The network diameter that can be achieved in the network is MaxAge 1 In the state on delivery MaxAge 20 and the maximum diameter that can be achieved 19 If you set the maximum value of 40 for MaxAge the maximum diameter that can be achieved 39 UM RedundConfig MSP Release 2 0 02 2013 35 Spanning Tree 3 1 Basics MaxAge Every STP BPDU contains a MessageAge counter When a bridge is passed through the counter increases by 1 Before forwarding a STP BPDU the bridge compares the MessageAge counter with the MaxAge value defined in the device IF MessageAge lt MaxAge the bridge forwards the STP BPDU to the next bridge If MessageAge MaxAge the bridge discards the STP BPDU Root Bridge gt MaxAge 5 Message Ton en Nessa ee Figure 20 Transmission of an STP BPDU depe
15. ce s neighbors no other ring participants are connected to the respective device All ring participants support the configuration time defined in the ring manager There is exactly 1 ring manager in the ring If you are using VLANs configure every ring port with the following settings Deactivate ingress filtering see the Switching VLAN Port dialog Define the port VLAN ID PVID see the Switching VLAN Port dialog PVID 1 if the device transmits the MRP data packets untagged VLAN ID 0 in Redundancy MRP dialog PVID any if the device transmits the MRP data packets in a VLAN VLAN ID 2 1 in Redundancy MRP dialog Define egress rules see Switching VLAN Static dialog U untagged if the device transmits the MRP data packets untagged VLAN ID 0 in Redundancy MRP dialog T tagged if the device transmits the MRP data packets in a VLAN VLAN ID 2 1 in Redundancy MRP dialog UM RedundConfig MSP Release 2 0 02 2013 17 Media Redundancy Protocol MRP 2 5 Example Configuration 2 5 Example Configuration A backbone network contains 3 devices in a line structure To increase the availability of the network you convert the line structure to a redundant ring structure Devices from different manufacturers are used All devices support MRP On every device you define ports 1 1 and 1 2 as ring ports N ou N N ul JI Figure 6 Example
16. domain modify operation Activates the MRP Ring enable When all the ring participants are configured close the line to the ring To do this you connect the devices at the ends of the line via their ring ports Check the messages from the device show mrp Displays the parameters for checking UM RedundConfig MSP Release 2 0 02 2013 25 Media Redundancy Protocol MRP 2 5 Example Configuration The Operation field shows the operating state of the ring port Possible values gt forwarding Port is switched on connection exists gt blocked Port is blocked connection exists gt disabled Port is disabled gt not connected No connection exists r Operation On C Off o Port 1 gt rRing Port 2 E Port E v Port 12 v Configuration Ring Manager On Coffi Advanced Mode Iv Ring Recovery 500ms 200ms VLAN ID OO EE Configuration error error on ringport link Set Reload Delete ring configuration Help Figure 13 Messages in the Operation field UM RedundConfig MSP 26 Release 2 0 02 2013 Media Redundancy Protocol MRP 2 5 Example Configuration The Information field shows messages for the redundancy configuration and the possible causes of errors The following messages are possible if the device is operating as a ring client or a ring manager Redundancy Available The redundancy is set up When a component of the ring is down the redundant line t
17. e fig 21 for determining the root path The Administrator has performed the following Leftthe default value of 32 768 8000H for every bridge apart from bridge 1 and bridge 5 and assigned to bridge 1 the value 16 384 4000H thus making it the root bridge To bridge 5 he assigned the value 28 672 7000H 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 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 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 UM RedundConfig MSP 4 Release 2 0 02 2013 Spanning Tree 3 3 Examples Root Bridge P BID 16 384 xh P BID 32768 P BID 32768 P BID 32 768 xl L P BID 32768 P BID 28672 Se ee 5 P BID Priority of the bridge identifikation BID BID without MAC Add
18. e 1 Network with line star and tree topologies To ensure that the communication is maintained when a connection fails you install additional physical connections between the network nodes Redundancy protocols ensure that the additional connections remain switched off while the original connection is still working If the connection fails the redundancy protocol generates a new path from the sender to the receiver via the alternative connection To introduce redundancy onto layer 2 of a network you first define 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 UM RedundConfig MSP Release 2 0 02 2013 Q Network Topology vs Redundancy 1 1 Network topologies Protocols 1 1 Network topologies 1 1 1 Meshed topology For networks with star or tree topologies redundancy procedures are only possible in connection with physical loop creation The result is a meshed topology Uc X xF amp A 2 amp Xx 4x Figure 2 Meshed topology Tree topology with physical loops UM RedundConfig MSP 10 Release 2 0 02 2013 Network Topology vs Redundancy 1 1 Network topologies Protocols For operating in this network topology the device provides you with the following redundancy protocols Rapid Spanning Tree RSTP 1 1 2 Ring topology In networks with a line topology you can use redundancy procedures by conn
19. ecting the ends of the line This creates a ring topology ARHXHXHXHx N See ey ee ce ee ee es ee ee es ee ee S Figure 3 Ring topology Line topology with connected ends For operating in this network topology the device provides you with the following redundancy protocols Media Redundancy Protocol MRP Rapid Spanning Tree RSTP UM RedundConfig MSP Release 2 0 02 2013 11 Network Topology vs Redundancy 1 2 Redundancy Protocols Protocols 1 2 Redundancy Protocols For operating in different network topologies the device provides you with the following redundancy protocols Redundancy Network topology Comments protocol MRP Ring The switching time can be selected and is practically independent of the number of devices An MRP Ring consits of up to 50 devices that support the MRP protocol according to IEC 62439 If you only use Hirschmann devices up to 100 devices are possible in the MRP Ring RSTP Random structure The switching time depends on the network topology and the number of devices typ lt 1 s with RSTP typ lt 30 s with STP Table 1 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 every port If the flow control and the redundancy function are active at the same time the redundancy may not work as intended UM RedundConfig MSP 12 Release 2
20. ee Port roles RSTP UM RedundConfig MSP Release 2 0 02 2013 59 63 36 11 12 13 17 29 31 33 37 32 34 34 34 45 Port State Protection functions guards R Rapid Spanning Tree Reconfiguration Reconfiguration time MRP Redundancy Redundant connections Ring Ring manager RM function Root Bridge Root guard Root Path Cost Root path Root port RSTP RST BPDU S STP compatibility STP BPDU Symbol T TCN guard Technical Questions Topology Change flag Training Courses Tree structure Spanning Tree 48 57 11 11 12 45 6 Index 68 UM RedundConfig MSP Release 2 0 02 2013 Further Support 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 hirschmann 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 hac support belden com in the America region at Tel 1 717 217 2270 E mail inet support us belden com in the Asia Pacific region at Tel 65 6854 9860 E mail inet ap belden com Hirschmann Competence Center The Hirschmann Competence Center is ahead of its competitors Consulting incorporates comprehensive technical advice from system evaluation through network planning to project planning Training
21. ement Software provides you with additional options for smooth configuration and monitoring Simultaneous configuration of multiple devices Graphical user interface with network layout Auto topology discovery Event log Event handling Client server structure Browser interface ActiveX control for SCADA integration SNMP OPC gateway UM RedundConfig MSP 6 Release 2 0 02 2013 Key Key The designations used in this manual have the following meanings List L 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 I Execution in the Graphical User Interface Execution in the Command Line Interface Symbols used WLAN access point Router with firewall Switch with firewall Router Switch UM RedundConfig MSP Release 2 0 02 2013 T N ey El B D Bridge Hub A random computer Configuration Computer Server PLC Programmable logic controller I O Robot UM RedundConfig MSP Release 2 0 02 2013 Network Topology vs Redundancy Protocols 1 Network Topology vs Redundancy Protocols When using Ethernet an important prerequisite is that data packets follow a single unique path from the sender to the receiver The following network topologies support this prerequisite Line topology Star topology Tree topology Figur
22. fected 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 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 3 4 5 STP compatibility mode The STP compatibility mode allows you to operate RSTP devices in networks with old installations If an RSTP device detects an older STP device it switches on the STP compatibility mode at the relevant port UM RedundConfig MSP 5O Release 2 0 02 2013 Spanning Tree 3 5 Configuring the device 3 5 Configuring the device RSTP configures the network topology completely independently The device with the lowest bridge priority automatically becomes the root bridge However to define a specific network structure regardless you specify a device as the root bridge In general a device in the backbone takes on this role Set up the network to meet your requirements initially without redundant lines You deactivate the flow control on the participating ports If the flow control and the redundancy function are active at the same ti
23. forwarding if the port does not receive any more STP BPDUs If this situation occurs the device designates the loop status of the port as inconsistent but does not forward any data packets UM RedundConfig MSP Release 2 0 02 2013 59 Spanning Tree 3 6 Guards 3 6 1 Activating the BPDU Guard Open the Redundancy Spanning Tree Global dialog Select the BPDU Guard checkbox Protocol Version r Operation Con Con KB Protocol Configuration Information Bridge Root Topology Bridge ID 4096 008064cattee 4096 008064catfee Bridge is Root Vv Priority 4096 fase i Rot Pot bo HeloTimets Po i Root Path Cost o Forward Delay s fi 5 fi 5 Topology Change Count fo Max Age Fr Fu Time Since Topology Change 0 day s 3 48 03 Tx Hold Count fi 0 BPDU Guard Iv Set Reload Help Figure 31 Activating the BPDU Guard Click on Set to save the changes enable Switch to the privileged EXEC mode configure Switch to the Configuration mode spanning tree bpdu guard Activates the BPDU Guard show spanning tree global Displays the parameters for checking UM RedundConfig MSP 60 Release 2 0 02 2013 Spanning Tree 3 6 Guards Open the Redundancy Spanning Tree Port dialog Switch to the CIST tab For terminal device ports select the checkbox in the Admin Edge Port column CIST Guaras Oper Oper Edge Port PointToPoint disable T mic enab d sablec 4 00
24. ically 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 18 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 UM RedundConfig MSP 38 Release 2 0 02 2013 Spanning Tree 3 2 Rules for Creating the Tree Structure Determine root path no Path with lowest path costs root path Equal path costs Path with highest priority in bridge identification root path Equal priority in bridge identification Use the bridge with lowest MAC address designated bridge Equal Path with highest port priority port priority root path Path with lowest port number of designated bridge root path Root path determined Figure 21 Flow diagram for specifying the root path UM RedundConfig MSP Release 2 0 02 2013 Spanning Tree 3 3 Examples 3 3 Examples 3 3 1 Example of determining the root path You can use the network plan see fig 22 to follow the flow chart see fig 21 for determining the root path The administrator has specified a priority in the bridge
25. ice is operating as root bridge show spanning tree global Displays the parameters for checking UM RedundConfig MSP 54 Release 2 0 02 2013 Spanning Tree 3 5 Configuring the device If applicable change the values in the Forward Delay and Max Age fields The root bridge transmits the changed values to the other devices Operation Protocol Version On off Rs r Protocol Configuration Information Bridge Root Topology Bridge ID 4096 00 80 64 ca ff ee s096 00 80 64 ca ff ee Bridge is Root v Priority a096 ba s096 Root Port jo Hello Time s 2 2 Root Path Cost f Forward Delay s 15 15 Topology Change Count 2 Max Age bo 20 Time Since Topology Change fo day s 0 05 51 Tx Hold Court fi 0 BPDU Guard Iv Set Reload Help m Figure 29 Changing Forward Delay and Max Age Click on Set to save the changes spanning tree forward time Defines the delay time for the status change in LA a 0 gt seconds spanning tree max age Specifies the maximum permissible branch lt 6 40 gt length i e the number of devices to the root bridge show spanning tree global Displays the parameters for checking Note The parameters Forward Delay and Max Age have the following relationship Forward Delay2 Max Age 2 1 If you enter values in the fields that contradict this relationship the device replaces these values with the last valid values or with the default value UM RedundConfig MSP Release
26. 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 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 Port 1 lt Port 3 UM RedundConfig MSP 40 Release 2 0 02 2013 Spanning Tree 3 3 Examples Root Bridge P BID 16 384 Ed P BID 32 768 P BID 32 768 P BID 32768 EJ P BID 32768 P BID 32768 Port 3 MAC 00 01 02 03 04 06 MAC 00 01 02 03 04 05 l 5 Port 1 P BID Priority of the bridge identifikation BID P BID 30768 BID without MAC Address Root path Interrupted path Figure 22 Example of determining the root path UM RedundConfig MSP Release 2 0 02 2013 41 Spanning Tree 3 3 Examples 3 3 2 Example of manipulating the root path You can use the network plan see fig 23 to follow the flow chart se
27. ing the advanced mode mrp domain modify Activates the advanced mode advanced mode enabled UM RedundConfig MSP Release 2 0 02 2013 23 Media Redundancy Protocol MRP 2 5 Example Configuration In the Ring Recovery field select the value 200ms Operation On Off Ring Port 1 Ring Port 2 Port faa v Port 12 v Operation notConnected Operation notConnected _ Configuration Ring Manager On off Advanced Mode Iv VLAN ID Information m Set Reload Delete ring configuration Help Figure 11 Defining the time for the ring recovery mrp domain modify Defines 200ms as the max delay time for the recovery delay 200ms reconfiguration of the ring 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 I O Leave the value in the VLAN field as 0 UM RedundConfig MSP 24 Release 2 0 02 2013 Media Redundancy Protocol MRP 2 5 Example Configuration L Switch the operation of the MRP Ring on Operation Ring Port 1 Ring Port 2 Port fia v Port 12 v Operation notConnected Operation JnotConnected Configuration Ring Manager On C Off Advanced Mode Iw Ring Recovery C 500ms 200ms VLAN ID Information Set Reload Delete ring configuration Help Figure 12 Switching on the MRP function Click on Set to save the changes mrp
28. itional 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 UM RedundConfig MSP Release 2 0 02 2013 Spanning Tree 3 4 The Rapid Spanning Tree Protocol BID 16384 1 BID 20480 BID 24576 P BID Priority of the bridge identifikation BID BID without MAC Address Root path Interrupted path C Root port Designated port ll Alternate port lll Backup port lt gt Edge port Figure 25 Port role assignment UM RedundConfig MSP Release 2 0 02 2013 AT Spanning Tree 3 4 The Rapid Spanning Tree Protocol 3 4 2 Port states Depending on the tree structure and the state of the selected connection paths the RSTP assigns the ports their states STP port state Administrative MAC RSTP Active topolog
29. k into a line structure You define the maximum time for the reconfiguration of the line in the ring manager Possible values for the maximum delay time e 9500 ms e 200 ms Note You only configure the reconfiguration time with a value less than 500 ms if all the devices in the ring support the shorter delay time Otherwise the devices that only support longer delay times might not be reachable due to overloading Loops can occur as a result UM RedundConfig MSP Release 2 0 02 2013 15 Media Redundancy Protocol MRP 2 3 Advanced mode 2 3 Advanced mode Fortimes even shorter than the guaranteed reconfiguration times the device provides the advanced mode The advanced mode speeds up the link failure recognition when the ring participants inform the ring manager of interruptions in the ring via link down notifications Hirschmann devices support link down notifications Therefore you generally activate the advanced mode in the ring manager If you are using devices that do not support link down notifications the ring manager reconfigures the line in the selected maximum reconfiguration time UM RedundConfig MSP 16 Release 2 0 02 2013 Media Redundancy Protocol MRP 2 4 Prerequisites for MRP 2 4 Prerequisites for MRP Before setting up an MRP Ring make sure that the following conditions are fulfilled All ring participants support MRP The ring participants are connected to each other via the ring ports Apart from the devi
30. ly supports RSTP works together with MSTP devices by not assigning an MST region to itself but rather the CST Common Spanning Tree UM RedundConfig MSP 30 Release 2 0 02 2013 Spanning Tree 3 1 Basics 3 1 Basics Because RSTP is a further development ofthe STP all the following descriptions ofthe STP also apply to the RSTP 3 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 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 RedundConfig MSP Release 2 0 02 2013 31 Spanning Tree 3
31. mation 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 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 Did you discover any errors in this manual If so on what page UM RedundConfig MSP Release 2 0 02 2013 65 Readers Comments Suggestions for improvement and additional information General comments Sender Company Department Name Telephone no Street Zip code City e mail Date Signature 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 66 UM RedundConfig MSP Release 2 0 02 2013 Index B Index A Advanced Mode Alternate port B Backup port BPDU BPDU guard Bridge Identifier Bridge Protocol Data Unit C Compatibility STP D Delay time MRP Designated bridge Designated port Diameter Spanning Tree Disabled port E Edge port F FAQ H HiView Industrial HiVision L Loop guard M MaxAge MRP Network load Path costs Port Identifier Port number Port priority Spanning Tr
32. me there is a risk that the redundancy function will not operate as intended Default setting flow control deactivated globally and activated on all ports LI Switch MRP off on all devices Switch Spanning Tree on on all devices in the network In the state on delivery Spanning Tree is switched on on the device UM RedundConfig MSP Release 2 0 02 2013 51 Spanning Tree 3 5 Configuring the device 52 Open the Redundancy Spanning Tree Global dialog Activate the function r Operation 7 Protocol Version Co Cot R Protocol Te Information Bridge Root Topology Bridge ID 32768 006064catfee 3276800 8064caffee Bridge is Root V Priority 32768 v zs 2 RootPort bo HeloTimets Po i Root Path Cost o Forward Delay s hs fs Topology Change Count o Max Age Fr Fr Time Since Topology Change loday s 41458 TxHoldCount ho BPDU Guard u Set Reload Help Figure 26 Switching the function on Click on Set to save the changes enable Switch to the privileged EXEC mode configure Switch to the Configuration mode spanning tree operation Switches Spanning Tree on show spanning tree global Displays the parameters for checking UM RedundConfig MSP Release 2 0 02 2013 Spanning Tree 3 5 Configuring the device L1 Now connect the redundant lines Define the settings for the device that takes over the role of the root bridge In the Priority field you enter a numerically lower
33. nding on MaxAge 36 UM RedundConfig MSP Release 2 0 02 2013 Spanning Tree 3 2 Rules for Creating the Tree Structure 3 2 Rules for Creating the Tree Structure 3 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 3 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 thatthe path costs between each individual bridge and the root bridge become as small as possible UM RedundConfig MSP Release 2 0 02 2013 37 Spanning Tree 3 2 Rules for Creating the Tree Structure 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 numer
34. not selected for this port The device designates the port In the Redundancy Spanning Tree Port dialog CIST tab the device shows the value enable in the BPDU Guard Effect column CIST Guards Root TCN Loop Loop Trans Trans BPDU Guard Guard Guard State into Loop out of Loop Guard Effect YO Aaa YA aa YA aT Set Reload Help Figure 33 Port dialog Guards tab show spanning tree port x y Displays the parameters of the port for checking The value of the BPDU Guard Effect parameter IS enable To reset the status of the device port to the value forwarding you proceed as follows If the device port is still receiving BPDUs Remove the manual definition as an edge port or Deactivate the BPDU Guard Activate the device port again UM RedundConfig MSP 62 Release 2 0 02 2013 Spanning Tree 3 6 Guards 3 6 2 Activating Root Guard TCN Guard Loop Guard Open the Redundancy Spanning Tree Port dialog Switch to the Guards tab For designated ports select the checkbox in the Root Guard column For ports that receive STP BPDUs with a Topology Change flag select the checkbox in the TCN Guard column For root alternate or backup ports select the checkbox in the Loop Guard column O OF OU CIST Guards Root TCN Loop Loop Trans Trans BPDU Guard Guard Guard State into Loop out of Lo
35. ny STP BPDUs If an attacker still attempts to feed in STP BPDUs at this port the device deactivates the device port Root Guard for designated ports You activate this protection function separately for every device port UM RedundConfig MSP Release 2 0 02 2013 5 Spanning Tree 3 6 Guards Root x ostile root If a designated port receives an STP BPDU with better path information to the root bridge the device discards the STP BPDU and sets the transmission state of the port to discarding instead of root If there are no STP BPDUs with better path information to the root bridge after 2 x Hello Time the device resets the state of the port to a value according to the port role TCN Guard for ports that receive STP BPDUs with a Topology Change flag You activate this protection function separately for every device port Root UM RedundConfig MSP 58 Release 2 0 02 2013 Spanning Tree 3 6 Guards If the protection function is activated the device ignores Topology Change flags in received STP BPDUs This does not change the content of the address table FDB of the device port However additional information in the BPDU that changes the topology is processed by the device Loop Guard for root alternate and backup ports You activate this protection function separately for every device port Root This protection function prevents the transmission status of a port from unintentionally being changed to
36. ociated 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 hirschmann com Printed in Germany Hirschmann Automation and Control GmbH Stuttgarter Str 45 51 72654 Neckartenzlingen Germany Tel 49 1805 141538 Rel 2 0 02 2013 11 02 2013 Contents Contents 2 1 2 2 2 3 2 4 2 9 3 1 3 2 3 3 About this Manual Key Network Topology vs Redundancy Protocols Network topologies 1 1 1 Meshed topology 1 1 2 Ring topology Redundancy Protocols Media Redundancy Protocol MRP Network Structure Reconfiguration time Advanced mode Prerequisites for MRP Example Configuration Spanning Tree Basics 3 1 1 The tasks of the STP Bridge parameters Bridge Identifier Root Path Cost Port Identifier Max Age and Diameter D WWWww D HNAWN s for Creating the Tree Structure Bridge information Setting up the tree structure ples Example of determining the root path Example of manipulating the root path Example of manipulating the tree structure WWWM Wo www oD 3j3 N UM RedundConfig MSP Release 2 0 02 2013 Contents 3 4 The Rapid Spanning Tree Protocol 45 3 4 1 Port roles 45 3 4 2 Port states 48 3 4 3 Spanning Tree Priority Vector 49 3 4 4 Fast reconfiguration 49 3 4 5 STP compatibility mode 50 3 5 Configuring the device 51 3 6 Guards 57 3
37. offers you an introduction to the basics product briefing and user training with certification The current technology and product training courses can be found at http www hicomcenter com Support ranges from the first installation through the standby service to maintenance concepts UM RedundConfig MSP Release 2 0 02 2013 69 Further Support 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 UM RedundConfig MSP 70 Release 2 0 02 2013 Further Support UM RedundConfig MSP Release 2 0 02 2013 11 h HIRSCHMANN ABELDEN BRAND
38. op Guard Effe 1 L E L false i 7 dis 2 false 1j J dis false I i ct apie apie apie k k k k disable disable al k k k TAAA TT u u ln jun ln u ln u Im TOUT TAY SA Set Reload Figure 34 Activating Guards Note The Root Guard and Loop Guard functions are mutually exclusive If you switch on the Root Guard function while the Loop Guard function is switched on the device switches off the Loop Guard function Click on Set to save the changes UM RedundConfig MSP Release 2 0 02 2013 63 Spanning Tree 64 enable configure interface x y spanning tree guard root spanning tree guard tcn spanning tree guard loop exit show spanning tree port x y 3 6 Guards Switch to the privileged EXEC mode Switch to the Configuration mode Switches to the interface mode Switches the Root Guard on at the designated port Switches on the TCN Guard on the port that receives STP BPDUs with a Topology Change flag Switches the Loop Guard on ata root alternate or backup port Leaves the interface mode Displays the parameters of the port for checking UM RedundConfig MSP Release 2 0 02 2013 Readers Comments 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 infor
39. ration phase You deactivate the flow control on the participating ports If the flow control and the redundancy function are active at the same time there is a risk that the redundancy function will not operate as intended Default setting flow control deactivated globally and activated on all ports Switch Spanning Tree off on all devices in the network Open the Redundancy Spanning Tree Global dialog Switch off the function In the state on delivery Spanning Tree is switched on on the device Operation Protocol Version Con off IRSTP Protocol Configuration Information Bridge Root Topology Bridge ID 32768 00 80 64 ca ff ee 32768 00 80 64 ca ff ee Bridge is Root iv Priority 32788 zs Root Port bo HeloTimets 2 2 Root Path Cost Forward Delay s hs hs o Topology Change Count Max Age Bo 0 Vu Time Since Topology Change 0 day s 4 14 58 Tx Hold Count fi 0 BPDU Guard u Set Reload Help Figure 7 Switching the function off enable Switch to the privileged EXEC mode configure Switch to the Configuration mode no spanning tree operation Switches Spanning Tree off show spanning tree global Displays the parameters for checking UM RedundConfig MSP 20 Release 2 0 02 2013 Media Redundancy Protocol MRP 2 5 Example Configuration L1 Switch MRP on on all devices in the network Open the Redundancy MRP dialog Define the desired ring ports Operation Con off
40. ree 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 3 4 1 Port roles RSTP assigns each bridge port one of the following roles see fig 25 Root Port This is the port at which a bridge receives data packets with the lowest path costs from the root bridge If there are multiple ports with equally low path costs the bridge ID of the bridge that leads to the root designated bridge decides which of its ports is given the role of the root port by the bridge further removed from the root If a bridge has multiple ports with equally low path costs to the same bridge the bridge uses the port ID of the bridge leading to the root designated bridge to decide which port it selects locally as the root port see fig 21 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 lf 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 UM RedundConfig MSP Release 2 0 02 2013 45 Spanning Tree 3 4 The Rapid Spanning Tree 46 Protocol Edge port Every network segment with no add
41. ress Root path P BID 32768 Interrupted path Figure 23 Example of manipulating the root path UM RedundConfig MSP Release 2 0 02 2013 43 Spanning Tree 3 3 Examples 3 3 3 Example of manipulating the tree structure The Management Administrator soon discovers that this configuration with bridge 1 as the root bridge see on page 40 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 24 The path costs for most of the bridges to the root bridge have decreased Root Bridge P BID 16 384 Ed P BID 32768 P BID 32768 P BID 32768 P BID 32768 Port 2 jx x Jx l Port 1 MAC 00 01 02 03 04 0 l l P BID 32768 P BID 32768 5 Jx MAC 00 01 02 03 04 06 P BID Priority of the bridge identifikation BID BID without MAC Address Root path Interrupted path Figure 24 Example of manipulating the tree structure UM RedundConfig MSP 44 Release 2 0 02 2013 Spanning Tree 3 4 The Rapid Spanning Tree Protocol 3 4 The Rapid Spanning Tree Protocol The RSTP uses the same algorithm for determining the t
42. the message was sent Port identifiers of the ports through which the message was received 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 3 4 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 default setting and then waits for the Hello Time to elapse to be sure that no bridge sending BPDUs is connected When the user ensures that a terminal device is connected at this port and will remain connected there are no waiting times 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 alternate 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 UM RedundConfig MSP Release 2 0 02 2013 49 Spanning Tree 3 4 The Rapid Spanning Tree Protocol 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 af
43. y bridge port operational Port state port role state DISABLED Disabled FALSE Discarding Excluded disabled DISABLED Enabled FALSE Discarding Excluded disabled BLOCKING Enabled TRUE Discarding Excluded alternate backup LISTENING Enabled TRUE Discarding Included root designated LEARNING Enabled TRUE Learning Included root designated FORWARDING Enabled TRUE Forwarding Included root designated Table 4 Relationship between port state values for STP and RSTP a The dotid MIB displays Disabled b The dotid MIB displays Blocked 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 STP BPDUs Learning Address learning active FDB and no data traffic except for STP BPDUs Forwarding Address learning is active FDB sending and receipt of all frame types not only STP BPDUs UM RedundConfig MSP 48 Release 2 0 02 2013 Spanning Tree 3 4 The Rapid Spanning Tree Protocol 3 4 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
Download Pdf Manuals
Related Search