L2 / L3 Switches Spanning Tree Configuration Guide
Contents
1. end Configure the spanning tree port priority as 64 for the MST instance 10 on the port ex 0 1 SMIS configure terminal SMIS config interface ex 0 1 SMIS config if spanning tree mst 10 port priority 64 SMIS config if end 1 10 Path Cost When spanning tree detects that multiple paths to the root switch are in a loop condition it selects the port with lowest path cost as the forwarding port In case of multiple ports having the same path cost to the root switch spanning tree selects the port with lowest numeric port priority value as the forwarding port The default path cost for the ports are calculated based on the port speed The table below shows the default path costs for different speed Port Speed Default Path Cost 10 Mbps 2000000 100 Mbps 200000 1 Gbps 20000 10 Gbps 2000 40 Gbps 500 Follow the steps below to change the spanning tree path cost for ports Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt Enters the port interface mode or interface range lt interface type gt lt interface id gt interface type may be any of the following gigabitethernet gi extreme ethernet ex qx ethernet qx port channel po Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide interface id is in slot port format for all physical interfaces It may b2. 40 as port fast SMIS config interface range gi 0 1 40 SMIS config if spanning tree portfast Warning portfast should only be enabled on ports connected to a single host Connecting hubs concentrators switches bridges etc to this interface when portfast is enabled can cause temporary bridging loops Use with CAUTION SMIS config if exit Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide Configure switch C as the root switch for VLAN 200 instance SMIS config spanning tree mst 2 priority 4096 SMIS config end Check the spanning tree MST configurations SMIS show spanning tree mst 2 detail MSTO2 Vlans mapped 200 Bridge Address 00 30 48 e3 56 12 Priority 4096 Root Address 00 30 48 e3 56 12 Priority 4096 Root this switch for MSTO2 Gi0 47 of MSTO2 is Designated Forwarding Port info port id 128 47 priority 128 cost 200000 Designated root address 00 30 48 e3 56 12 priority 4096 cost 0 Designated bridge address 00 30 48 e3 56 12 priority 4096 port id 128 47 SMIS Save this spanning tree configuration SMIS write startup config Building configuration Please wait May take a few minutes OK SMIS Supermicro L2 L3 Switches Configuration Guide
3. KA AWA 15 1 9 Port Priority E DD N lace ciwenaccnetcthcctex Seas chevelachuastaccedetatacoutwbanstaet aE a aaa e aa a aaea 16 Ee B E EE 18 TII Hello TiM sects ee Nee a a Ree edd ge dar 20 TIZ Max EE 22 1 13 Zell leet TEE 23 LIA Max HOPS EE 24 1 15 Path Cost Loris Shorterin eene Eege u k ra ar seyek nz 25 1 16 Transmit Hole COUMt ic a Liseya GEERT aa a Sa S z a Aa D ya eae ANA AA 26 1 17 R Ot GUAM TT 27 1 18 Topology Change Guard 28 T C R DD r siti EE E eosin dees 30 E SATO Ed EE 31 121 LIK TY E 32 1 22 Spanning Tree Configuration Examples kk kk kk kk kk kk K k ka kk KA A KA A KA KA KA A KA 34 Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide 1 Spanning Tree Configuration Guide This document describes the Spanning Tree feature supported in Supermicro Layer 2 Layer 3 switch products This document covers the Spanning Tree configurations for the below listed Supermicro switch products Top of Rack Switches Blade Switches e SSE G24 TG4 e SBM GEM X2C e SSE G48 TG4 e SBM GEM X2C e SSE X24S e SBM GEM X3S e SSE X3348S e SBM XEM X10SM e SSE X3348T The majority of this document applies to all the above listed Supermicro switch products In any particular sub section however the contents might vary across these switch product models In those sections the differences are clearly identified with reference to particular switch product models If any part
4. channel identifier for port channel interfaces To configure multiple interfaces use the interface range command To provide a range use a hyphen between the start and end interface numbers E g int range gi 0 1 10 To provide multiple interfaces or ranges separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 To configure the hello time in MST mode spanning tree mst hello time lt time value gt Configures the hello time interval time value Hello time value may be 1 or 2 seconds The default hello time is 2 seconds Step 4 end Exits the configuration mode Step 5 show spanning tree bridge hello time Displays the spanning tree hello time Step 6 write startup config Optional step saves this spanning tree configuration to be part of startup configuration Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide The no spanning tree mst hello time command resets the spanning tree port hello time to the default value of 2 seconds The examples below show various ways to configure the spanning tree port hello time Configure the spanning tree port hello time as 1 second in RST mode SMIS configure terminal SMIS config spanning tree hello time 1 SMIS config end Configure the MSTP hello time as 1 second for port gi 0 1 SMIS configure terminal SMIS config interface gi 0 1 SMIS config if sp
5. ports Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt Enters the port interface mode or interface range lt interface type gt lt interface id gt interface type may be any of the following gigabitethernet gi extreme ethernet ex qx ethernet qx port channel po interface id is in slot port format for all physical interfaces It may be the port channel identifier for port channel interfaces Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide To configure multiple interfaces use the interface range command To provide a range use a hyphen between the start and end interface numbers E g int range gi 0 1 10 To provide multiple interfaces or ranges separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 spanning tree restricted role Enables the root guard feature The default option is the root guard feature being disabled Step 4 end Exits the configuration mode Step 5 show spanning tree detail Displays the spanning tree root guard information Step 6 write startup config Optional step saves this spanning tree configuration to be part of startup configuration The no spanning tree restricted role command resets the root guard feature to the default value of disabled The examp
6. tree switch priority to the default value of 32768 In MST mode it resets the switch priority for the default MST E instance to O The no spanning tree mst lt instance id gt priority command resets the spanning tree switch priority to the default value of 32768 for the given MST instance The examples below show various ways to configure the spanning tree switch priority Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide Configure the spanning tree switch priority as 4096 in RST mode SMIS configure terminal SMIS config spanning tree priority 4096 SMIS config end Configure the spanning tree switch priority as 4096 for the default MST instance 0 SMIS configure terminal SMIS config spanning tree priority 4096 SMIS config end Configure the spanning tree switch priority as 4096 for the MST instance 10 SMIS configure terminal SMIS config spanning tree mst 10 priority 4096 SMIS config end 1 9 Port Priority When the spanning tree detects that multiple paths to the root switch are in a loop condition it selects the port with lowest path cost as the forwarding port In case of multiple ports having the same path cost to the root switch spanning tree selects the port with the lowest numeric port priority value as the forwarding port When the priorities of all the ports are the same the port with lowest port identifier gets selected as the forwarding port Follow t
7. Region name e Revision number e Instance to VLAN mapping Follow the steps below to configure the MST region parameters Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 spanning tree mst configuration Enters the MST configuration mode Step 3 instance lt instance id 1 16 gt vlan lt vlan range gt Creates an MST instance and maps it to the given VLAN range instance id The MST instance identifier may be from 1 to 16 vian range may be any VLAN number or list of VLAN numbers Multiple VLAN numbers can be provided as comma separated values Consecutive VLAN numbers can be provided as a range such as 5 10 User can configure VLANs with identifiers 1 to 4069 Step 4 name lt name string gt Configures the MST region name name string Alphanumeric case sensitive string with maximum length of 32 characters Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide The default name is the system MAC address Step 5 revision lt revision number gt Configures the MST region revision number revision number The MST revision number may be from 0 to 65535 The default revision number is 0 Step 6 end Exits the configuration mode Step 7 show spanning tree mst configuration Displays the spanning tree MST configuration parameters Step 8 write startup config Optional step saves this spannin
8. SUPERMICR L2 L3 Switches Spanning Tree Configuration Guide Revision 1 1 Spanning TreeConfiguration Guide The information in this USER S MANUAL has been carefully reviewed and is believed to be accurate The vendor assumes no responsibility for any inaccuracies that may be contained in this document makes no commitment to update or to keep current the information in this manual or to notify any person or organization of the updates Please Note For the most up to date version of this manual please see our web site at www supermicro com Super Micro Computer Inc Supermicro reserves the right to make changes to the product described in this manual at any time and without notice This product including software if any and documentation may not in whole or in part be copied photocopied reproduced translated or reduced to any medium or machine without prior written consent IN NO EVENT WILL SUPERMICRO BE LIABLE FOR DIRECT INDIRECT SPECIAL INCIDENTAL SPECULATIVE OR CONSEQUENTIAL DAMAGES ARISING FROM THE USE OR INABILITY TO USE THIS PRODUCT OR DOCUMENTATION EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES IN PARTICULAR SUPERMICRO SHALL NOT HAVE LIABILITY FOR ANY HARDWARE SOFTWARE OR DATA STORED OR USED WITH THE PRODUCT INCLUDING THE COSTS OF REPAIRING REPLACING INTEGRATING INSTALLING OR RECOVERING SUCH HARDWARE SOFTWARE OR DATA Any disputes arising between manufacturer and customer shall be gove
9. anning tree configuration to be part of startup configuration Spanning tree decides the link type based on the duplex mode of the ports It detects full duplex ports as point to point links and half duplex ports as a shared LAN links Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide The point to point links are assumed to be connected directly to another spanning tree switch The shared LAN links are assumed to be connected to multiple switches through hubs In point to point links spanning tree negotiates with other end switches to move the ports rapidly to the forwarding state Users can override the type of ports as either point to point links or as shared links Follow the steps below to configure the link type of the ports Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt Enters the port interface mode or interface range lt interface type gt lt interface id gt interface type may be any of the following gigabit ethernet gi extreme ethernet ex qx ethernet qx port channel po interface id is in slot port format for all physical interfaces It may be the port channel identifier for port channel interfaces To configure multiple interfaces use the interface range command To provide a range use a hyphen between the start and end in
10. anning tree mst hello time 1 SMIS config if end 1 12 Max Age Switches maintain the BPDU information for every port for a maximum age period If BPDU configuration messages are not received on any ports within the max age time the switch will reconfigure those ports Max age time affects failure detection and reconfiguration A smaller max age time will help detect failures quickly It is advisable to choose a max age time based on the maximum number of switches on the network between any two hosts The default max age time is 20 seconds Oo The max age value should be less than twice of forward time 1 Follow the steps below to change the max age time Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 To configure the max age time Configures the switch spanning tree spanning tree max age lt age value gt max age time Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide age value Spanning tree max age value may be from 6 to 40 seconds The default max age is 20 Step 3 end Exits the configuration mode Step 4 show spanning tree bridge max age Displays the spanning tree configuration parameters including the show spanning tree switch priority values Step 5 write startup config Optional step saves this spanning tree configuration to be part of startup configuration Oo The no spanni
11. be part of startup configuration The no spanning tree forward time command resets the spanning tree forwarding time to the default value of 15 The example below shows how to configure the spanning tree forward time Configure the forwarding time as 12 seconds SMIS configure terminal SMIS config spanning tree forward time 12 SMIS config end 1 14 Max Hops MSTP uses a hop count to decide the validity of the BPDU messages The root switch sends a BPDU with a hops count as the max hops Every switch decrements the hops count while forwarding the BPDU When this hops count reaches zero the switch discards the BPDU message The default max hops is 20 Follow the steps below to change the max hops Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 To configure the max age time Configures the switch MSTP max hops spanning tree mst max hops lt Mmaxhops value gt value maxhops value MSTP max hops value may be from 6 to 40 seconds The default max hops is 20 Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide Step 3 end Step 4 show spanning tree mst Exits the configuration mode Displays the spanning tree max hops along with other MST information Optional step saves this spanning tree configuration to be part of startup configuration Step 5 write startup config The no spannin
12. blocked to form a loop free topology The spanning tree algorithm assigns one of the following roles to every port on the switches sbort to reach the root switch with lowest path cost Root Po rt Root ports forward the traffic eLoop free connection to the other switch on the LAN e Designated ports forward the traffic Designated Port Port e Redundant path to the root switch e Alternate ports do not forward the traffic Alternate Redundant path to other switches on the LAN Blocked Port Blocked ports do not forward the traffic When a network connection status changes spanning tree recalculates the paths to form a loop free topology Spanning tree calculations are based on the following three key factors Bridge Identifier Combination of a switch s MAC address and switch s spanning tree priority Path Cost Spanning tree path cost to the root switch Port Identifier Combination of port number and port priority When a switch boots up it assumes its role as the root switch It sends out spanning tree BPDUs with its bridge id as the root bridge id When a switch receives spanning tree BPDUs it compares the received BPDU information If the received BPDU information is superior the switch uses the received BPDU information to determine the root bridge and recalculates the spanning tree If the received BPDU information is inferior the switch ignores the received BPDU Spanning tree operates the switch ports in different stat
13. cause any loops Those ports can be configured with the port fast feature to start forwarding the traffic immediately instead of waiting through the learning and listening states Configure the port fast feature only to the ports that are connected to computers and servers Configuring port fast on the ports that are connected to other switches might cause network loops The port fast feature is disabled on all ports by default Follow the steps below to enable the port fast feature on the ports Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt Enters the port interface mode or interface range lt interface type gt lt interface id gt interface type may be any of the following gigabitethernet gi extreme ethernet ex qx ethernet qx port channel po interface id is in slot port format for all physical interfaces It may be the port channel identifier for port channel interfaces To configure multiple interfaces use the interface range command To provide a range use a hyphen between the start and end interface numbers E g int range gi 0 1 10 Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide To provide multiple interfaces or ranges separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 spanning tree portfast E
14. e the port channel identifier for port channel interfaces To configure multiple interfaces use the interface range command To provide a range use a hypen between the start and end interface numbers E g int range gi 0 1 10 To provide multiple interfaces or ranges use separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 To configure the port priority in RST mode spanning tree cost lt cost value gt To configure the port priority for the default MST instance 0 spanning tree cost lt cost value gt To configure the port priority for a particular MST instance Configures the port spanning tree path cost cost value Spanning tree port priority value may be from 0 to 200000000 The default path cost is calculated based on the port speed spanning tree mst lt nstance id gt cost lt cost instance id The MST instance value gt identifier may be from 1 to 16 Step 4 end Exits the configuration mode Step 5 show spanning tree interface lt interface type gt Displays the spanning tree port lt interface ia gt parameters including the port path cost values Step 6 Ki write startup config Optional step saves this spanning tree configuration to be part of startup configuration The no spanning tree cost command resets the spanning tree port path cost to the default value In MST mode it resets the port path cost for the defau
15. en the priorities of all switches are the same the switch with the lowest MAC address gets elected as the root switch Follow the steps below to change the spanning tree priority Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 To configure the switch priority in RST mode Configures the switch spanning tree spanning tree priority lt priority value gt priority priority value Spanning tree switch To configure the switch priority for the default MST priority value in multiples of 4096 from instance 0 0 to 61440 In other words only the spanning tree priority lt priority value gt following priority values are valid To configure the switch priority for a particular MST 0 4096 8192 12288 instance 16384 20480 24576 28672 spanning tree mst lt nstance id gt priority lt priority 32768 36864 40960 45056 value gt 49152 53248 57344 61440 The default priority value is 32768 instance id The MST instance identifier may be from 1 to 16 Step 3 end Exits the configuration mode Step 4 show spanning tree bridge priority Displays the spanning tree configuration parameters including the show spanning tree switch priority values Step 5 write startup config Optional step saves this spanning tree configuration to be part of startup configuration The no spanning tree priority command resets the spanning
16. es while calculating the loop free topology BPDU exchanges between switches take a few seconds in a large LAN To avoid any temporary loops while forming spanning tree topology the switch ports are moved through different states to reach a forwarding state Switch ports stay in one of the following spanning tree states Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide eReceives BPDUs eDiscards packets Does not learn MAC Blocking Receives BPDUs Disabled Discards packets Does not learn MAC e Does not receive BPDUs Discards packets S Receives BPDUS Does not learn MAC eDiscards packets eLearns MAC addresses Since spanning tree forms a logical loop free topology it helps to have physical loop connections on the network for redundancy purposes When an active connection fails spanning tree enables the blocked eReceives BPDUs eForwards packets eLearns MAC addresses redundant connection automatically Rapid spanning tree protocol RSTP provides faster topology convergence While spanning tree STP takes more than 30 seconds to move a port to a forwarding state RSTP can move a port to the forwarding state within 3 times of the hello interval the default hello interval is 2 seconds RSTP is compatible with STP Multiple spanning tree protocol MSTP extends RSTP to provide separate spanning trees for different VLANs or VLAN groups This helps use alternate paths e
17. fficiently by only blocking the ports for the required VLANs MSTP is compatible with RSTP 1 1 1 Root Switch Election Procedure Spanning tree protocol selects one switch as the root switch for every switched LAN This root switch is used as the reference point to decide the spanning tree topology Based on the connections to this root switch the redundant links on the LAN are identified and blocked Spanning tree runs an election process to determine the root switch Spanning tree selects the switch with the lowest bridge ID as the root switch Every switch on the LAN has a bridge ID The bridge ID has two components its priority and the MAC address of the switch The spanning tree priority occupies the most significant two bytes of the bridge ID The default spanning tree priority is 32768 Supermicro L2 L3 Switches Configuration Guide EBRII Spanning TreeConfiguration Guide STP Priority 2 bytes Switch MAC 6 bytes Default 32768 Bridge ID When a switch starts spanning tree it sends out BPDUs with its bridge ID as the root bridge ID When a switch receives the BDPUs it compares the received root bridge ID with its own bridge ID If the received root bridge ID is lower than its own bridge ID the received switch accepts the other switch as the root switch If the received root bridge ID is higher than its own bridge ID the received switch ignores the received BPDU and continue to act as the root switch If the pri
18. formation in this document is subject to change without notice Other products and companies referred to herein are trademarks or registered trademarks of their respective companies or mark holders Copyright 2013 by Super Micro Computer Inc All rights reserved Printed in the United States of America Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide Contents 1 Spanning Tree Configuration Guide ic xilklclakklakllke lake la kalak sakal akele kan n de a kaka ke kek kelek k EW a d kuW kun ku n 4 1 1 Spanning Tree Ee 4 1 1 1 Root Switch Election Procedure ek kek Ek ek kk KEKE KEK ANAK KAKE KAKE KAKE KA HE KAKA 6 1 2 Spanning Tree tele Le dE H 1 3 Spanning Tree Defaults cccccccsscsssececseececsecesseecsseeeseeecsaeesssaecseseeceaeesesaaeesseeeceaeeessaeessaeeseateeees 7 1 4 Enabling Disabling Spanning Tree 8 1 4 1 Enable Disable Spanning Tree Global 8 1 4 2 Enable Disable Spanning Tree on Portz 9 1 5 CONTISULING MSs x e _ _oe e_ _ _o_o _e_e_ _ e _ _ _ a 10 1 5 1 Configuring MST region and instances l lhlhElii kk kek ke kek k KAKA KAKA KAKA KA KA RA 11 1 6 Configuring RST P oiiire aaa a aaa a Eege 13 1 7 Spanning Tree Compatibility ssssirirseirssiscissorsrsastrisredersnsodssrssoanrri drederen nenin ans assat iare HAH h LH 13 1 8 Configuring Root Switch or Priority kek kek ke kek kak ka k KE KA ka KA KA kk KA KA
19. g tree configuration to be part of startup configuration OD The no name command removes the configured MST region name E The no revision command resets the configured MST region revision number to its default value of 0 The no instance lt instance id 1 16 gt vlan lt vian range gt command removes the VLANs from a given MST instance The no instance lt instance id 1 16 gt command deletes the given MST instance The examples below show various ways to configure MST region parameters Configure the MST region with name dc1_region revision number 1 and map the VLANs 100 to 300 to MST instance 10 SMIS configure terminal SMIS config spanning tree mst configuration SMIS config mst name dc1_region SMIS config mst revision 1 SMIS config mst instance 10 vlan 100 300 SMIS config mst end Remove the VLANs 201 to 250 from MST instance 10 SMIS configure terminal SMIS config spanning tree mst configuration Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide SMIS config mst no instance 10 vlan 201 250 SMIS config mst end Delete the MST instance 10 SMIS configure terminal SMIS config spanning tree mst configuration SMIS config mst no instance 10 SMIS config mst end 1 6 Configuring RSTP Spanning tree is enabled by default in MST mode in Supermicro switches Follow the steps below to change to RSTP Ste
20. g tree mst max hops command resets the MST max hops to the default value of 20 The example below shows how to configure the MSTP max hops Configure the MST max hops as 30 SMIS configure terminal SMIS config spanning tree mst max hops 30 SMIS config end 1 15 Path Cost Long Short Spanning tree was originally designed with 16 bit path costs This was good enough for fast Ethernet and Gigabit Ethernet speed links but not enough for 10Gb and higher speed ports Hence spanning tree protocol introduced support for 32 bit path costs The 16 bit path costs method is referred to as the short path cost method and the 32 bit path cost method is referred to as the long path costs method In MSTP and RSTP mode Supermicro switches support long path costs by default In STP compatible RSTP mode Supermicro switches uses short path costs by default Follow the steps below to change the path costs method Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 To configure the path cost method as short Configures the path cost method spanning tree pathcost method short In MSTP and RSTP the default path cost method is long In STP compatible RSTP To configure the path cost method as long mode the default path cost is short spanning tree pathcost method long Step 3 end Exits the configuration mode Step 4 show spanning tree pathcost method Displays the spanning tree pat
21. globally Follow the steps below to disable the spanning tree globally Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 no spanning tree Disables the spanning tree globally Step 3 end Exits the configuration mode Step 4 show spanning tree Displays the spanning tree information Step 5 write startup config Optional step saves this spanning tree configuration to be part of startup configuration O The spanning tree command enables the spanning tree globally The examples below show ways to disable enable the spanning tree function on Supermicro switches Disable the spanning tree SMIS configure terminal SMIS config no spanning tree Supermicro L2 L3 Switches Configuration Guide Em Spanning TreeConfiguration Guide SMIS config end Enable the spanning tree SMIS configure terminal SMIS config spanning tree SMIS config end 1 4 2 Enable Disable Spanning Tree on Ports Spanning tree is enabled by default on all the ports and port channels in Supermicro switches Follow the steps below to disable the spanning tree on ports Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt or interface range lt interface type gt lt interface id gt Enters the port interface mode interface type may be any of t
22. h cost Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide method information Step 5 write startup config Optional step saves this spanning tree configuration to be part of startup configuration The no spanning tree pathcost method command resets the path cost method to the default value The example below shows how to configure the path cost method Configure the path cost method as short SMIS configure terminal SMIS config spanning tree pathcost method short SMIS config end 1 16 Transmit Hold Count Transmit hold count helps to control the BPDU burst traffic A switch limits the number of BPDUs sent in a second by the transmit hold count A higher transmit hold count value allows switches to send more BPDUs for faster convergence However this might lead to high switch CPU utilization The default transmit hold count is 3 Follow the steps below to change the transmit hold count value Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 spanning tree transmit hold count lt count_value gt Configures the transmit hold count value Count value Transmit hold count value may be from 1 to 10 The default transmit hold count value is 3 Step 3 end Exits the configuration mode Step 4 show spanning tree detail Displays the spanning tree hold count information Step 5 write startup co
23. he following gigabit ethernet gi extreme ethernet ex qx ethernet qx port channel po interface id is in slot port format for all physical interfaces It may be the port channel identifier for port channel interfaces To configure multiple interfaces use the interface range command To provide a range use a hypen between the start and end interface numbers E g int range gi 0 1 10 To provide multiple interfaces or ranges separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 To disable the spanning tree in RST mode spanning tree disable To disable the default MST instance spanning tree spanning tree disable To disable the particular MST instance spanning Disables the spanning tree on the port instance id The MST instance identifier may be from 1 to 16 Supermicro L2 L3 Switches Configuration Guide Es Spanning TreeConfiguration Guide tree spanning tree mst lt instance ia gt disable Step 4 end Exits the configuration mode Step 5 show spanning tree interface lt nterface type gt lt interface ia gt lt interface ia gt show running config interface lt interface type gt Displays the spanning tree port information Step 6 write startup config Optional step saves this spanning tree configuration to be part of startup configuration Oo no spanning tree disable command enables the span
24. he steps below to change the spanning tree port priority Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt Enters the port interface mode or interface range lt interface type gt lt interface id gt interface type may be any of the following gigabitethernet gi extreme ethernet ex qx ethernet qx port channel po interface id is in slot port format for all physical interfaces It may be the port channel identifier for port channel interfaces Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide To configure multiple interfaces use the interface range command To provide a range use a hypen between the start and end interface numbers E g int range gi 0 1 10 To provide multiple interfaces or ranges separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 To configure the port priority in RST mode Configures the port spanning tree spanning tree port priority lt priority value gt priority priority value Spanning tree port To configure the port priority for the default MST priority value may be from 0 to 240 instance 0 Priority value must be a multiple of 16 spanning tree port priority lt priority value gt The default priority value is 128 To configure the port priority for a particular MST instance insta
25. hello time for RSTP Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 To configure the hello time in RST mode Configures the hello time interval spanning tree hello time lt time value gt time value Hello time value may be 1 or 2 seconds The default hello time is 2 seconds Step 3 end Exits the configuration mode Step 4 show spanning tree interface lt interface type gt Displays the spanning tree port lt interface id gt parameters including the hello time values Step 5 write startup config Optional step saves this spanning tree Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide configuration to be part of startup configuration Step The no spanning tree hello time command resets the spanning tree port hello time to the O default value of 2 seconds Follow the steps below to change the hello time for ports in MSTP Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt or interface range lt interface type gt lt interface id gt Enters the port interface mode interface type may be any of the following gigabitethernet gi extreme ethernet ex qx ethernet qx port channel po interface id is in slot port format for all physical interfaces It may be the port
26. icular switch product model is not referenced the reader can safely assume that the content is applicable to all the above listed models OD Throughout this document the common term switch refers to any of the above listed Supermicro switch product models unless a particular switch product model is noted 1 1 Spanning Tree Basics Switches are interconnected to provide network access to a large number of end stations In complex networks it is possible to have multiple network paths between any two end devices These multiple paths form network loops that lead to packet flooding by forwarding broadcast and multicast packets repeatedly over the looped connections Flooding makes the network unusable until the looped connections are disconnected and flooding stopped Spanning tree protocols help to prevent the flooding on network loops Spanning tree protocols form a loop free tree logically structured network topology over physical network connections Supermicro L2 L3 Switches Configuration Guide Fen Spanning TreeConfiguration Guide Spanning tree enabled switches exchange spanning tree protocol messages BPDU to form a loop free topology Based on the exchanged BPDU information the spanning tree algorithm selects one of the switches on the network as the root switch for the tree topology All other switches on the network choose a best loop free path to reach the root switch The redundant paths to root switch are then
27. le below shows how to enable the root guard feature Enable the root guard feature on ports ex 0 1 and ex 0 2 SMIS configure terminal SMIS config interface range ex 0 1 2 SMIS config if spanning tree restricted role SMIS config if end 1 18 Topology Change Guard The topology change guard feature helps to prevent unexpected topology changes Network administrators can configure the topology guard on ports that are not expected to receive topology change BPDUs Topology change BPDUs received on the topology change guard enabled ports will be dropped The topology guard feature is disabled on all the ports by default Follow the steps below to enable the topology guard feature on the ports Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt Enters the port interface mode or interface range lt interface type gt lt interface id gt interface type may be any of the following gigabit ethernet gi extreme ethernet ex qx ethernet qx port channel po interface id is in slot port format for all physical interfaces It may be the port channel identifier for port channel interfaces To configure multiple interfaces use the interface range command To provide a range use a hyphen between the start and end i
28. lt MST instance to 0 The no spanning tree mst lt instance id gt cost command resets the spanning tree port path cost to the default value for the given MST instance The examples below show various ways to configure the spanning tree port path cost Configure the spanning tree port path cost as 200 in RST mode on ports ex 0 1 and ex 0 2 SMIS configure terminal Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide SMIS config interface range ex 0 1 2 SMIS config if spanning tree cost 200 SMIS config if end Configure the spanning tree port priority as 200 for the default MST instance of 0 on port gi 0 1 SMIS configure terminal SMIS config interface gi 0 1 SMIS config if spanning tree cost 200 SMIS config if end Configure the spanning tree port priority as 20 for the MST instance 10 on port ex 0 1 SMIS configure terminal SMIS config interface ex 0 1 SMIS config if spanning tree mst 10 cost 20 SMIS config if end 1 11 Hello Time The root switch periodically sends the BPDU messages on every port for every hello time interval The default hello time is 2 seconds If switches do not receive BPDU messages for a period of 3 hello time intervals spanning tree protocol assumes the root switch has failed In MSTP the hello time is configurable on individual ports In RSTP the hello time is configured commonly for all the ports Follow the steps below to change the
29. nables the port fast feature The default setting is the port fast feature being disabled Step 4 end Exits the configuration mode Step 5 show spanning tree detail Displays the spanning tree port fast information Step 6 write startup config Optional step saves this spanning tree configuration to be part of startup configuration Oo The no spanning tree portfast command resets the port fast feature to the default value of disabled The example below shows how to enable the port fast feature Enable the port fast feature on ports ex 0 1 and ex 0 2 SMIS configure terminal SMIS config interface range ex 0 1 2 SMIS config if spanning tree portfast SMIS config if end 1 20 Auto Edge The auto edge feature helps to detect the other end of the device attached to the ports If no BPDU is received for a period of time on auto edge enabled ports the switch marks those parts as edge ports assuming those ports are not connected to other switches This helps to move the port to the forwarding state quickly Also switches do not send topology change notifications when an edge port s status changes The auto edge feature is enabled on all the ports by default Follow the steps below to configure the auto edge feature on the ports Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 interface lt interface type gt lt interface id gt Enter
30. nce id The MST instance spanning tree mst lt insiance id gt port priority identifier may be from 1 to 16 lt priority value gt Step 4 end Exits the configuration mode Step 5 show spanning tree interface lt interface type gt Displays the spanning tree port lt interface id gt parameters including the port priority values Step 6 write startup config Optional step saves this spanning tree configuration to be part of startup configuration The no spanning tree port priority command resets the spanning tree port priority to the default value of 128 In MST mode it resets the port priority for the default MST instance to ES 0 The no spanning tree mst lt instance id gt port priority command resets the spanning tree port priority to the default value of 128 for the given MST instance The examples below show various ways to configure the spanning tree port priority Configure the spanning tree port priority as 208 in RST mode on the ports ex 0 1 and ex 0 2 SMIS configure terminal SMIS config interface range ex 0 1 2 SMIS config if spanning tree port priority 208 SMIS config if end Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide Configure the spanning tree port priority as 112 for the default MST instance 0 on the port gi 0 1 SMIS configure terminal SMIS config interface gi 0 1 SMIS config if spanning tree port priority 112 SMIS config if
31. nfig Optional step saves this spanning tree configuration to be part of startup configuration Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide O The no spanning tree transmit hold count command resets the hold count to the default value of 3 The example below shows how to configure the transmit hold count value Configure the transmit hold count as 8 SMIS configure terminal SMIS config spanning tree transmit hold count 8 SMIS config end 1 17 Root Guard In spanning tree networks the position of the root switch is important to achieve optimized topology According to spanning tree protocol any switch can become a root switch based on its priority and switch MAC address Networks managed by multiple administrators can lead to multiple switches with lowest priority competing to become the root switch There is no option to block any switch becoming the root switch to maintain an optimized topology The root guard feature helps prevent any unexpected switch from becoming the root switch If the root guard feature is enabled on a port it prevents any switches connected to that port from becoming the root switch If any superior BPDU is received on the root guard enabled port a switch moves that port from the forwarding state to the listening state The root guard feature is disabled on all ports by default Follow the steps below to enable the root guard feature on the
32. ng tree max age command resets the spanning tree max age to the default value of 20 The example below shows how to configure the spanning tree max age Configure the max age as 12 SMIS configure terminal SMIS config spanning tree max age 12 SMIS config end 1 13 Forwarding Time A switch will wait for the of forwarding time interval on listening and learning states before going to a forwarding state The default forwarding time is 15 seconds Hence a switch waits for 15 seconds in the listening state and for another 15 seconds in the learning state before going to the forwarding state The forwarding time value should maintain the following relation with max age 2 Forward Time 1 gt Max Age Follow the steps below to change the forwarding time Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 To configure the max age time Configures the switch spanning tree spanning tree forward time lt time value gt max age time Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide time value Spanning tree forward time may be from 4 to 30 seconds The default forwarding time is 15 seconds Step 3 end Exits the configuration mode Step 4 show spanning tree bridge forward time Displays the spanning tree forward time Step 5 write startup config Optional step saves this spanning tree configuration to
33. ning tree on ports The examples below show various ways to disable enable the spanning tree on ports Disable the spanning tree on ports ex 0 1 and ex 0 2 SMIS configure terminal SMIS config interface range ex 0 1 2 SMIS config if spanning tree disable SMIS config end Enable the spanning tree on port ex 0 1 SMIS configure terminal SMIS config interface ex 0 1 SMIS config if no spanning tree disable SMIS config end 1 5 Configuring MST Spanning tree is enabled by default in MST mode in Supermicro switches In case the switch was earlier configured in RST mode follow the steps below to change to MST mode Step Command Description Step 1 configure terminal Enters the configuration mode Step 2 spanning tree mode mst Configures the switch to operate in MST mode Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide Step 3 end Exits the configuration mode Step 4 show spanning tree Displays the spanning tree mode information Step 5 write startup config Optional step saves this spanning tree configuration to be part of startup configuration Changing the spanning tree mode will shut down the currently running spanning tree and restart it in the new given mode 1 5 1 Configuring MST region and instances All the spanning tree switches in an MST region must have the same values configured for the following parameters e
34. nterface numbers E g int range gi 0 1 10 To provide multiple interfaces or ranges separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 spanning tree restricted tcn Enables the topology guard feature The default option is the topology guard feature being disabled Step 4 end Exits the configuration mode Step 5 show spanning tree detail Displays the spanning tree topology guard information Step 6 write startup config Optional step saves this spanning tree configuration to be part of startup configuration The no spanning tree restricted tcn command resets the topology guard feature to the default value of disabled The example below shows how to enable the topology guard feature Enable the topology guard feature on ports ex 0 1 and ex 0 2 SMIS configure terminal SMIS config interface range ex 0 1 2 Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide SMIS config if spanning tree restricted tcn SMIS config if end 1 19 Port Fast When a port link is up spanning tree does not allow the port to forward the packets immediately Instead it moves the port through listening and learning states before reaching the forwarding state This state machine function helps to achieve a loop free topology but delays the port operations in forwarding the traffic The switch ports connected to computers and servers are not expected to
35. ommand Description Step 1 configure terminal Enters the configuration mode Step 2 To force the spanning tree compatibility as STP Configures the spanning tree spanning tree compatibility stp compatibility To force the spanning tree compatibility as RSTP spanning tree compatibility rst To force the spanning tree compatibility as MSTP spanning tree compatibility mst Step 3 end Exits the configuration mode Step 4 show spanning tree Displays the spanning tree mode information Step 5 write startup config Optional step saves this spanning tree configuration to be part of startup configuration O mode to the default value The no spanning tree compatibility command resets the spanning tree compatibility The examples below show various ways to configure the spanning tree compatibility Configure the spanning tree compatibility as STP SMIS configure terminal SMIS config spanning tree compatibility stp SMIS config end Configure the spanning tree compatibility as RSTP SMIS configure terminal SMIS config spanning tree compatibility rst SMIS config end Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide 1 8 Configuring Root Switch or Priority The switch with the lowest priority value gets elected as the root switch To define any particular switch as the root switch assign it a lower numeric priority value The default spanning tree priority is 32768 Wh
36. orities of all switches are the same the switch MAC addresses decide the lowest bridge ID and hence the switch with the lowest MAC address will be elected as the root switch 1 2 Spanning Tree Support Supermicro switches support STP RSTP and MSTP protocols based on standards IEEE 802 1D 2004 and 802 1s 1 3 Spanning Tree Defaults Parameter Default Value Spanning tree global status Enabled Spanning tree port status Enabled Spanning tree mode MST Switch priority 32768 Port priority 128 Port cost Port Speed Default Path Cost 10 Mbps 2000000 100 Mbps 200000 1 Gbps 20000 10 Gbps 2000 40 Gbps 500 Hello time 2 seconds Forwarding time 15 seconds Maximum aging time 20 seconds Transmit hold count 3 Max hops 20 Path cost method long Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide MST region name Switch MAC address MST region revision 0 Spanning tree compatibility In MSTP mode the default compatibility is MSTP and in RSTP mode the default compatibility is RSTP Root guard Disabled Topology change guard Disabled Port fast Disabled Auto edge Enabled Link type Full duplex ports point to point links Half duplex ports shared LAN links 1 4 Enabling Disabling Spanning Tree 1 4 1 Enable Disable Spanning Tree Globally Spanning tree is enabled by default in Supermicro switches
37. p Command Description Step 1 configure terminal Enters the configuration mode Step 2 spanning tree mode rst Configures the switch to operate in RSTP mode Step 3 end Exits the configuration mode Step 4 show spanning tree Displays the spanning tree mode information Step 5 write startup config Optional step saves this spanning tree configuration to be part of startup configuration Changing the spanning tree mode will shut down the currently running spanning tree and restart it in the new given mode 1 7 Spanning Tree Compatibility MSTP is backward compatible with RSTP and STP Similarly RSTP is backward compatible with STP When an MSTP operating switch detects an RSTP operating switch in any port the MSTP switch will downgrade to RSTP operating mode on that port Similarly when an MSTP or RSTP operating switch detects an STP operating switch in any port the switch will downgrade to STP operating mode on that port Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide Users can force the switch to operate in any particular compatibility mode In user configured STP compatible mode switches will transmit and receive only STP BPDUs and will drop any RSTP and MSTP BPDUS received In MSTP mode the default compatibility is MSTP and in RSTP mode the default compatibility is RSTP Follow the steps below to configure the spanning tree compatibility Step C
38. ree portfast Warning portfast should only be enabled on ports connected to a single host Connecting hubs concentrators switches bridges etc to this interface when portfast is enabled can cause temporary bridging loops Use with CAUTION Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide SMIS config if exit Configure switch B as the root switch for the VLAN 100 instance SMIS config spanning tree mst 1 priority 4096 SMIS config end Check the spanning tree MST configurations SMIS show spanning tree mst 1 detail MSTO1 VLANs mapped 100 Bridge Address 00 30 48 a1 11 01 Priority 4096 Root Address 00 30 48 a1 11 01 Priority 4096 Root this switch for MSTO1 Gi0 47 of MSTO1 is Designated Forwarding Port info port id 128 47 priority 128 cost 200000 Designated root address 00 30 48 a1 11 01 priority 4096 cost 0 Designated bridge address 00 30 48 a1 11 01 priority 4096 port id 128 47 SMIS Save this spanning tree configuration SMIS write startup config Building configuration Please wait May take a few minutes OK SMIS Configurations on Switch C SMIS configure terminal Create VLANs 100 and 200 SMIS config vlan 100 200 SMIS config vlan exit Create MST instance for VLANs 100 and 200 SMIS config spanning tree mst configuration SMIS config mst instance 1 vlan 100 SMIS config mst instance 2 vlan 200 SMIS config mst exit Configure port gi 0 1
39. rned by the laws of Santa Clara County in the State of California USA The State of California County of Santa Clara shall be the exclusive venue for the resolution of any such disputes Super Micro s total liability for all claims will not exceed the price paid for the hardware product FCC Statement This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the manufacturer s instruction manual may cause harmful interference with radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case you will be required to correct the interference at your own expense California Best Management Practices Regulations for Perchlorate Materials This Perchlorate warning applies only to products containing CR Manganese Dioxide Lithium coin cells Perchlorate Material special handling may apply See http www dtse ca gov hazardouswaste perchlorate for further details Manual Revision 1 0 Release Date February 24 2013 Unless you request and receive written permission from Super Micro Computer Inc you may not copy any part of this document In
40. rt fast Figure MSTP Eg 1 Spanning Tree MSTP Configuration Example Switch C Configurations on Switch A Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide SMIS configure terminal Create VLANs 100 and 200 SMIS config vlan 100 200 SMIS config vlan exit Create MST instance for VLANs 100 and 200 SMIS config spanning tree mst configuration SMIS config mst instance 1 vlan 100 SMIS config mst instance 2 vlan 200 SMIS config mst exit Configure port gi 0 1 40 as port fast SMIS config interface range gi 0 1 40 SMIS config if spanning tree portfast Warning portfast should only be enabled on ports connected to a single host Connecting hubs concentrators switches bridges etc to this interface when portfast is enabled can cause temporary bridging loops Use with CAUTION SMIS config if exit Save this spanning tree configuration SMIS write startup config Building configuration Please wait May take a few minutes OK SMIS Configurations on Switch B SMIS configure terminal Create VLANs 100 and 200 SMIS config vlan 100 200 SMIS config vlan exit Create MST instance for VLANs 100 and 200 SMIS config spanning tree mst configuration SMIS config mst instance 1 vlan 100 SMIS config mst instance 2 vlan 200 SMIS config mst exit Configure port gi 0 1 40 as port fast SMIS config interface range gi 0 1 40 SMIS config if spanning t
41. s the port interface mode or interface range lt interface type gt lt interface id gt interface type may be any of the Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide following gigabit ethernet gi extreme ethernet ex qx ethernet qx port channel po interface id is in slot port format for all physical interfaces It may be the port channel identifier for port channel interfaces To configure multiple interfaces use the interface range command To provide a range use a hyphen between the start and end interface numbers E g int range gi 0 1 10 To provide multiple interfaces or ranges separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 To enable the auto edge spanning tree auto edge To disable the auto edge no spanning tree auto edge Enables or disables the auto edge feature The default setting is the auto edge feature being enabled Step 4 end Exits the configuration mode Step 5 show spanning tree detail Displays the spanning tree auto edge information Step 6 write startup config The example below shows how to disable the auto edge feature Disable the auto edge feature on ports ex 0 1 and ex 0 2 SMIS configure terminal SMIS config interface range ex 0 1 2 SMIS config if no spanning tree auto edge SMIS config if end 1 21 Link Type Optional step saves this sp
42. terface numbers E g int range gi 0 1 10 To provide multiple interfaces or ranges separate with a comma E g int range gi 0 1 10 gi 0 20 Step 3 To configure the link type as point to point Configures the link type spanning tree link type point to point To configure the link type as shared spanning tree link type shared Step 4 end Exits the configuration mode Step 5 show spanning tree detail Displays the spanning tree auto edge information Step 6 write startup config Optional step saves this spanning tree configuration to be part of startup configuration Supermicro L2 L3 Switches Configuration Guide Spanning TreeConfiguration Guide The no spanning tree link type command resets the user configured link type to let the switch detect the link type based on the duplex mode The example below shows how to configure the link type Configure port gi 0 1 as a point to point link SMIS configure terminal SMIS config interface gi 0 1 SMIS config if spanning tree link type point to point SMIS config if end 1 22 Spanning Tree Configuration Examples Configure the following requirements on the switches as shown below in Figure MSTP Eg 1 Configure two MST instances separately for VLAN 100 and 200 Configure switch B as the root switch for the VLAN 100 instance Configure switch C as the root switch for the VLAN 200 instance Pie Nae Configure port gi 0 1 40 in all the switches as po
Download Pdf Manuals
Related Search