Abstract. GAK; Reviewed: WCH 8/14/2003. Solution & Interoperability Test Lab Application Notes 2003 Avaya Inc. All Rights Reserved.

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1 Rapid Reconfiguration Spanning Tree Protocol (RSTP) 802.1w Sample Configurations for Avaya P882/P580 Gigabit Ethernet Switches with Third Party Vendors including Cisco, HP and Foundry - Issue 1.0 Abstract These Application Notes describe two RSTP sample configurations with Avaya P882/P580 Gigabit Ethernet Switches: Stage 1 Basic Switch-to-Switch RSTP Redundancy and Stage 2 Advanced Partial Mesh RSTP Redundancy. Use of the Hunt Group feature for forming Link Aggregation Groups (LAGs) in conjunction with redundant low-speed trunks is demonstrated. Two configuration diagrams have been included along with provisioning notes. These Application Notes were created to support network engineers implementing fully RSTP compatible configurations in a switched Layer 2 environment. 1 of 20

2 1. Introduction The IEEE 802.1w Rapid Reconfiguration Spanning Tree Protocol (RSTP) was developed to decrease the recovery time of redundant paths in Layer 2 networks. The 802.1w standard is backward compatible with traditional 802.1D capable bridges, although interoperability with such bridges diminishes the performance advantages achieved by operating a full RSTP network. The 802.1D STP feature has been replaced with 802.1w RSTP in Avaya P580/P882 Gigabit Ethernet switch supervisor software release 6.0. This new capability significantly reduces the spanning tree re-convergence time of 30 seconds (typical of 802.1D bridges) down to 5 seconds or less. RSTP accomplishes this reduction in re-convergence time by combining some of the 802.1D STP port states together as depicted below in Table 1. Table 1: RSTP Port State Comparison STP (802.1D) Port State Disabled Blocking Listening Learning Forwarding RSTP (802.1w) Port State Discarding Discarding Discarding Learning Forwarding The 802.1D root port and designated port roles remain the same in 802.1w; however, the blocking port role is now split into backup and alternate port roles. The alternate port provides an alternate path in the direction of the root bridge in the event that the root port fails. The backup port provides an alternate path in the direction of the leaves of the spanning tree in the event that a designated port fails. RSTP only achieves rapid transition to the forwarding state on edge ports and point-to-point links. All ports directly connected to host end stations are designated as edge ports because they cannot create bridging loops in the network. As a result, edge ports can transition directly to the forwarding state, bypassing the listening and learning port states. It is important to note that once an edge port receives a BPDU from another bridge, it immediately becomes a non-edge port even when the port is configured manually as an edge port. Point-to-point links are any links which are full duplex. If a port negotiates to half-duplex, it is considered a shared link and can no longer rapidly transition to the forwarding state. These Application Notes address two configurations: Stage 1 Basic Switch-to-Switch RSTP Redundancy and Stage 2 Advanced Partial Mesh RSTP Redundancy. The Stage 1 configuration depicted in Figure 1 demonstrates high speed 802.1Q trunks and Link Aggregation Groups (LAGs) backed up by redundant low speed 802.1Q trunks in a switch-toswitch arrangement. The Stage 2 configuration depicted in Figure 2 adds additional redundant low speed 802.1Q trunks between some of the switches that were not interconnected previously in Stage 1. 2 of 20

3 MST Region 0 Cisco Catalyst /14 PC /24 3/15 3/1 Avaya (TM) P882 Gig Ethernet Switch 3/3 PC /24 3/1 3/7 Avaya (TM) P580 Gig Ethernet Switch 3/5 Avaya (TM) P333R Stackable Switch 2/10 3/11 4/1 5/2 5/1 1/51 1/2 2/13 2/11 LAG 3/12 4/5 LAG 5/6 4/2 3/2 5/5 LAG 1/52 1/1 5/2 5/6 3/2 PC /24 LAG 3/1 3/2 4/2 Foundry BigIron HP Procurve 2524 PC /24 100BaseTX Access Link 100BaseTX Redundant Trunk 4/3 PC / BaseT Trunk 1000BaseSX Trunk PC /24 Figure 1: Basic Switch-to-Switch RSTP Redundancy MST Region 0 Cisco Catalyst /14 PC /24 3/15 3/1 Avaya (TM) P882 Giga Ethernet Switch 3/3 PC /24 3/7 3/1 Avaya (TM) P580 Gig Ethernet Switch 3/5 Avaya (TM) P333R Stackable Switch 2/12 2/10 3/11 4/1 5/2 5/1 1/51 1/2 1/3 2/13 2/11 LAG 3/12 4/5 LAG 5/6 4/2 3/2 5/5 LAG 1/52 1/1 5/2 5/6 3/2 PC /24 LAG 3/1 3/2 4/2 Foundry BigIron HP Procurve PC /24 4/4 4/5 100BaseTX Access Link 100BaseTX Redundant Trunk 4/3 PC / BaseT Trunk 1000BaseSX Trunk PC /24 Figure 2: Advanced Partial Mesh RSTP Redundancy 3 of 20

4 1.1. Design Methodology All switch ports are designated with edge port = false by default, which disables the rapid transition to forwarding feature. Throughout these Application Notes edge ports (client ports) are manually provisioned with edge port = true to ensure that these ports rapidly transition to the forwarding state upon link up. If an edge port detects a BPDU from another bridge, which was connected accidentally, the operation of the edge port will change to false and the port will participate in the topology. All switch-to-switch trunk and LAG trunk ports are forced as point-to-point. All switch-toswitch trunks are full duplex so automatic detection is unnecessary. The point-to-point auto detection capability will only change to shared if the link suddenly negotiates to half duplex. This should never happen on a switch-to-switch trunk. The Auto Flush on Link Down feature is enabled on all trunk ports and Hunt Groups in the sample configurations. This feature flushes the Forwarding Data Base (FDB) for the VLAN automatically upon link failure of a port. This helps ensure that fast switchover of appropriate traffic flows to forwarding ports occurs. Automatic settings may be used, but many administrators prefer a more granular approach to managing critical network parameters, which is why static settings are demonstrated in these Application Notes. 2. Equipment and Software Validated The following equipment and software were used for the sample configuration provided: Equipment Avaya P580 Gigabit Ethernet Switch 1 M8000R-SUP module 1 M8048R-100TX module 1 M8008R-GB module 1 M8008R-1000T module Avaya P882 Gigabit Ethernet Switch 1 M8000R-SUP module 1 M8024R-100TX module 1 M8008R-GB module 1 M8008R-1000T module Avaya P333R Stackable Switch 1 X330G2 Expansion module Cisco Catalyst 6509 Switch 1 WS-X6K-SUP2-2GE module 1 WS-6348 module HP Procurve J4832A 100/100T module Foundry BigIron B8GMR3-A module 1 B8GC module Software Version 6.0 Gigabit Ethernet switch software RSTP (802.1w) Standard Supported Version 6.0 Gigabit Ethernet switch software RSTP (802.1w) Standard Supported Version switch software RSTP (802.1w) Standard Supported Version 7.5(1) CatOS software Version 12.1(3a)E4 IOS software MST (802.1s) Standard Supported Version F switch software RSTP (802.1w) Standard Supported Version bT53 switch software RSTP (802.1w) Standard Supported Supports a single instance RSTP database for the version validated. This requires that other interconnected vendors be configured for single instance RSTP in order to avoid loops within individual Virtual LANs. 4 of 20

5 1 B24E-A module Six PC s each equipped with an 100BaseTX capable network adaptor Microsoft Windows 2000 Professional 3. Rapid Spanning Tree 802.1w Configuration This section describes all of the commands and web agent navigations required to build the test configurations depicted in Figure 1 and Figure 2. To demonstrate two different ways of provisioning the P580/P882 switch family the P580 switch configuration is demonstrated using the Web Agent and the P882 switch configuration is shown via the CLI. This does not mean the user must perform administration in this way using these particular mechanisms. Any combination of the CLI, Web Agent or MultiService Network Management software may be used to provision either switch. The CLI and Web Agent mechanisms are demonstrated for informational purposes only P580 Switch Web Agent Administration This section depicts the provisioning steps for the P580, which can be applied to both Figure 1 and Figure 2 configurations. Similar steps could also be used to provision the P882 switch with minor changes to the modules/ports and hunt group names used. 1. Create a Virtual LAN on the switch. Select Cajun Router! L2 Switching! VLANs! Configuration from the Web Agent. The VLAN Configuration window opens. Click the CREATE button. The Create VLAN window opens (Figure 3). Enter a unique Virtual LAN name in the Name field (e.g. vlan100) and enter a unique VLAN ID in the ID field (e.g. 100) then click the APPLY button. Figure 3: Create VLAN 2. Enable Rapid Reconfiguration Spanning Tree Protocol (RSTP) on the switch. Select Cajun Router! L2 Switching! Spanning Tree from the Web Agent. The Spanning Tree Information window opens (Figure 4). Select IEEE 802.1D from the Configuration drop-down menu. Select Rapid Spanning Tree (2) from the Protocol Version drop-down menu, then click the APPLY button. 5 of 20

6 Note: The IEEE 802.1D indicates a single instance spanning-tree database, which is required when interconnecting to a P333R running code with RSTP enabled. 3. Configure all end station edge-ports. Figure 4: Spanning Tree Information (upper half) Select Cajun Router! Modules & Ports! Configuration from the Web Agent. The Module Information window opens (Figure 5). Figure 5: Module Information Select the switch ports for a module containing ports to be modified under the Switch Ports column (e.g. click on 48 for the 48 port Fast Ethernet module). The Switch Ports window opens (Figure 6). Figure 6: Switch Ports for Module 3 (modified for brevity) 6 of 20

7 Select Port 3.1 for port 3/1 under the Name column. The Switch Port Configuration for Port 3.1 window opens (Figure 7). Select vlan100 from the Port VLAN drop-down menu. Select edge-port from the Admin Edge Port drop-down menu then click the APPLY button. Figure 7: Switch Port Configuration for Port 3.1 (sample edge-port) 7 of 20

8 4. Configure all switch-to-switch trunk ports (execute on ports 3/2, 3/5, 3/7, 4/2, 5/1 and 5/2). Notes: Only the root ports need to be configured for the Hunt Groups. The other members inherit the configuration of the root port (the first port added to the Hunt Group). The root port is used for transporting all broadcast and unknown unicast traffic and is also responsible for transmitting spanning tree Bridge Protocol Data Units (BPDU s). Select Cajun Router! Modules & Ports! Configuration from the Web Agent. The Module Information window opens (Figure 8). Figure 8: Module Information Select the switch ports for a module containing ports to be modified under the Switch Ports column (e.g. click on 48 for the 48 port Fast Ethernet module). The Switch Ports window opens (Figure 9). Figure 9: Switch Ports for Module 3 (modified for brevity) Select Port 3.2 for port 3/2 under the Name column. The Switch Port Configuration for Port 3.2 window opens (Figure 10). 8 of 20

9 Select vlan100 from the Port VLAN drop-down menu. Select IEEE 802.1Q from the Trunk Mode drop-down menu. Select ForceTrue from the Admin Point-to-Point Link drop-down menu. Select non-edge-port from the Admin Edge Port drop-down menu. Select Enable from the Auto Flush on Link Down drop-down menu then click the APPLY button. Figure 10: Switch Port Configuration for Port 3.2 (sample switch-to-switch port) 9 of 20

10 5. Create all required Link Aggregation Groups (LAGs) on the switch with auto-flush enabled. Repeat for hunt group named P882 on ports 5/2 and 5/6, and the hunt group named P333R on ports 5/1 and 5/5. Select Cajun Router! L2 Switching! Hunt Groups from the Web Agent. The Hunt Group Configuration window opens. Click the CREATE button. The Create Hunt Group window opens (Figure 11). Enter a unique name for the Hunt Group in the Name field (e.g. P882). Select Enable from the Auto Flush drop-down menu and click the APPLY button. Figure 11: Create Hunt Group Select Cajun Router! Modules & Ports! Configuration from the Web Agent. The Module Information window opens (Figure 12). Figure 12: Module Information Select the switch ports for a module containing ports to be added to a Hunt Group under the Switch Ports column (e.g. click on 8 for the M8008R-1000GB module in slot 5). The Switch Ports window opens (Figure 13). 10 of 20

11 Figure 13: Switch Ports for Module 4 (modified for brevity) Select a switch port to add to a hunt group (e.g. select Port 5.2 for port 5/2 under the Name column). The Switch Port Configuration for Port 5.2 window opens (Figure 14). 11 of 20

12 Select the hunt group (e.g. P882) from the Hunt Group drop-down menu. Click the APPLY button. Repeat for all remaining member ports in the Hunt Group. Note: The first port added to the Hunt Group is automatically designated as the Hunt Group root port (flood port). Figure 14: Switch Port Configuration for Port 5.2 (sample switch-to-switch LAG port) 12 of 20

13 3.2. P882 Switch CLI Administration This section depicts the steps for provisioning the P882 used in Figure 1 and Figure 2. Similar steps could also be used to provision the P580 switch with minor changes to the modules/ports and hunt group names used. 1. Create a Virtual LAN on the switch (e.g. VLAN ID = 100). EIS-P882-A(configure)# set vlan 100 name vlan Assign the Virtual LAN to the required ports. EIS-P882-A(configure)# port vlan 3/1-3,3/12,3/15,4/1,5/2 100 Note: Only the root ports needs to be configured for the Hunt Groups. The other members inherit the configuration of the root port (the first port added to the Hunt Group). The root port is used for transporting all broadcast and unknown unicast traffic and is also responsible for transmitting spanning tree Bridge Protocol Data Units (BPDU s). 3. Enable 802.1Q trunking on all switch-to-switch ports. EIS-P882-A(configure)# set port trunking-format 3/12 ieee-802.1q EIS-P882-A(configure)# set port trunking-format 5/2 ieee-802.1q EIS-P882-A(configure)# set port trunking-format 4/1 ieee-802.1q 4. Enable the auto-flush feature on all single trunk ports. EIS-P882-A(configure)# set port auto-flush 3/2-3,3/15 enable 5. Create all required Link Aggregation Groups (LAGs) on the switch with auto-flush enabled. EIS-P882-A(configure)# set hunt group 6509 EIS-P882-A(configure)# set hunt group 8000 EIS-P882-A(configure)# set hunt group 580 EIS-P882-A(configure)# set hunt group auto-flush 6509 enable EIS-P882-A(configure)# set hunt group auto-flush 8000 enable EIS-P882-A(configure)# set hunt group auto-flush 580 enable EIS-P882-A(configure)# set port huntgroup 3/ EIS-P882-A(configure)# set port huntgroup 5/2,5/ EIS-P882-A(configure)# set port huntgroup 4/1,4/ Configure the switch for single instance RSTP and enable spanning tree. EIS-P882-A(configure)# set spantree version rapid-spanning-tree EIS-P882-A(configure)# set spantree config ieee EIS-P882-A(configure)# set spantree enable 802.1D Note: The version options are rapid-spanning-tree and common-spanning-tree 13 of 20

14 7. Save the switch running configuration. EIS-P882-A(configure)# copy run start 3.3. P333R Switch CLI Administration 1. Create a Virtual LAN on the switch (e.g. VLAN ID = 100). P330-1(super)# set vlan 100 name vlan Assign the Virtual LAN to the required ports. P330-1(super)# set port vlan 100 1/1-2 P330-1(super)# set port vlan 100 1/51-52 Add the following command when using the advanced (Figure 2) configuration: P330-1(super)# set port vlan 100 1/3 3. Enable 802.1Q trunking on all switch-to-switch ports. P330-1(super)# set trunk 1/51-52 dot1q P330-1(super)# set trunk 1/2 dot1q Add the following command when using the advanced (Figure 2) configuration: P330-1(super)# set trunk 1/3 dot1q 4. Enable RSTP globally on the switch. P330-1(super)# set spantree enable P330-1(super)# set spantree version rapid-spanning-tree 5. Designate all client ports as edge ports and all switch-to-switch trunk ports as non-edge ports. P330-1(super)# set port edge admin state 1/1 edge-port P330-1(super)# set port edge admin state 1/51-52 non-edge-port P330-1(super)# set port edge admin state 1/2 non-edge-port Note: Command options are edge-port, non-edge-port and auto. Add the following command when using the advanced (Figure 2) configuration: P330-1(super)# set port edge admin state 1/3 non-edge-port 6. Designate all full duplex trunk ports as point-to-point. 14 of 20

15 P330-1(super)# set port point-to-point admin status 1/51-52 forcetrue P330-1(super)# set port point-to-point admin status 1/2 force-true Note: Command options are force-true, force-false and auto. Add the following command when using the advanced (Figure 2) configuration: P330-1(super)# set port point-to-point admin status 1/3 force-true 7. Create all required Link Aggregation Groups (LAGs) on the switch. P330-1(super)# set port channel 1/51-52 on P Cisco Catalyst 6509 Switch CLI Administration 1. Create a Virtual LAN on the switch (e.g. VLAN ID = 100). Console> (enable) set vlan 100 name vlan Change the port VLAN binding methods to static instead of the default, dynamic. Console> (enable) set port membership 2/10-11 static Console> (enable) set port membership 2/13-14 static 3. Assign the Virtual LAN as the port VLAN for all client and switch-to-switch ports. Console> (enable) set vlan 100 2/10-11 Console> (enable) set vlan 100 2/13-14 Add the following command when using the advanced (Figure 2) configuration: Console> (enable) set vlan 100 2/12 4. Enable 802.1Q trunking on all switch-to-switch ports. Console> (enable) set trunk 2/10 on dot1q Console> (enable) set trunk 2/11 on dot1q Console> (enable) set trunk 2/14 on dot1q Add the following command when using the advanced (Figure 2) configuration: Console> (enable) set trunk 2/12 on dot1q 5. Restrict switch-to-switch trunk ports to allow Virtual LAN 100 only for security. 15 of 20

16 Console> (enable) clear trunk 2/ , , Console> (enable) clear trunk 2/ , , Console> (enable) clear trunk 2/ , , Add the following command when using the advanced (Figure 2) configuration: Console> (enable) clear trunk 2/ , , Create a static EtherChannel LAG with the neighboring P882 switch. Force the channel group number for the LAG as 882 to make troubleshooting and identification easier. Console> (enable) set port channel 2/10-2/ Console> (enable) set port channel 2/10-2/11 mode on 7. Modify the EtherChannel load sharing algorithm for optimal load distribution. Console> (enable) set port channel all distribution ip source 8. Enable Mono Spanning Tree (MST) 802.1s. MST is compatible with 802.1w and 802.1D. Console> (enable) set spanning-tree mode mst Console> (enable) set spantree mst config commit Note: Cisco 4000, 6000 and 6500 series switches do not support RSTP (802.1w) in its native form. Instead they support MST (802.1s), which is a compatibly modified version of RSTP (802.1w). MST instance 0 is used by default, which allows a common root to be negotiated between RSTP, MST and 802.1D STP. Do not use MST instances HP Procurve Switch 2524 CLI Administration 1. Create a Virtual LAN on the switch (e.g. VLAN ID = 100). HP ProCurve Switch 2524(config)# vlan 100 name vlan Assign the Virtual LAN untagged to client ports and tagged for switch-to-switch trunk ports. HP ProCurve Switch 2524(config)# vlan 100 tagged 2,25 HP ProCurve Switch 2524(config)# vlan 100 untagged 1 Add the following command when using the advanced (Figure 2) configuration: HP ProCurve Switch 2524(config)# vlan 100 tagged 3,4 3. Enable RSTP globally on the switch and force the version to rstp native operation. HP ProCurve Switch 2524(config)# spanning-tree protocol-version rstp 16 of 20

17 HP ProCurve Switch 2524(config)# spanning-tree force-version rstpoperation 4. Designate all client ports as edge ports and all switch-to-switch ports as non-edge ports. HP ProCurve Switch 2524(config)# spanning-tree ethernet 1 edge-port 5. Designate all full duplex switch-to-switch ports as point-to-point. HP ProCurve Switch 2524(config)# spanning-tree ethernet 25 point-topoint-mac force-true HP ProCurve Switch 2524(config)# spanning-tree ethernet 2 point-topoint-mac force-true Add the following additional commands when using the advanced (Figure 2) configuration: HP ProCurve Switch 2524(config)# spanning-tree ethernet 4 point-topoint-mac force-true HP ProCurve Switch 2524(config)# spanning-tree ethernet 3 point-topoint-mac force-true 6. Save the configuration file. HP ProCurve Switch 2524(config)# write mem 3.6. Foundry BigIron 8000 Switch CLI Administration 1. Create a Virtual LAN on the switch (e.g. VLAN ID = 100). BigIron Router(config)# vlan 100 name vlan100 by port 2. Assign the Virtual LAN untagged to client ports and tagged for switch-to-switch ports. BigIron Router(config-vlan-100)# tagged ethernet 3/1 BigIron Router(config-vlan-100)# tagged ethernet 3/2 BigIron Router(config-vlan-100)# tagged ethernet 4/2 BigIron Router(config-vlan-100)# untagged ethernet 4/3 Add the following commands when using the advanced (Figure 2) configuration: BigIron Router(config-vlan-100)# tagged ethernet 4/4 BigIron Router(config-vlan-100)# tagged ethernet 4/5 17 of 20

18 3. Configure a Link Aggregation Group and deploy (activate) it. BigIron Router(config)# trunk switch ethernet 3/1 to 3/2 BigIron Router(config)# trunk deploy 4. Enable single instance RSTP globally on the BigIron switch. BigIron Router(config)# spanning-tree single 802-1w 5. Enable spanning-tree for VLAN 100. BigIron Router(config-vlan-100)# spanning-tree 6. Enable forced point-to-point port status on all switch-to-switch trunk links. BigIron Router(config)# interfaced ethernet 3/1 BigIron Router(config-if-e1000-3/1)# spanning-tree 802-1w adminpt2pt-mac Note: Foundry only requires modification of the first port of a LAG trunk. BigIron Router(config-if-e1000-3/1)# interface ethernet 4/1 BigIron Router(config-if-e100-4/1)# spanning-tree 802-1w adminpt2pt-mac Add the following commands when using the advanced (Figure 2) configuration: BigIron Router(config-if-e100-4/1)# interface ethernet 4/4 BigIron Router(config-if-e100-4/4)# spanning-tree 802-1w adminpt2pt-mac BigIron Router(config-if-e100-4/4)# interface ethernet 4/5 BigIron Router(config-if-e100-4/5)# spanning-tree 802-1w adminpt2pt-mac 7. Enable forced edge port status on all client edge ports. BigIron Router(config)# interface ethernet 4/3 BigIron Router(config-if-e100-4/3)# spanning-tree 802-1w admin-edgeport 8. Save the configuration. BigIron Router(config-vlan-100)# write mem 18 of 20

19 4. Verification Steps 1. After connecting either configuration depicted, verify that no loops have occurred using RSTP and interface statistics. 2. Randomly disconnect high-speed links and observe that the redundant low-speed links rapidly transition to the forwarding state. Expect convergence times to be on the order of 5 seconds or less. A convergence time of 30 seconds or longer could mean that one or more bridges in the configuration are operating in legacy 802.1D Spanning Tree mode. If this happens check each switches STP mode. 3. Reconnect high-speed links and observe that they transition to the forwarding state and the corresponding low-speed links transition to blocking. 5. Conclusion Connectivity between all of the vendors depicted using 802.1w Rapid Reconfiguration Spanning Tree Protocol (RSTP) or a fully compatible version of spanning tree can be achieved by following the guidelines demonstrated in these Application Notes. The RSTP re-convergence times measured switch-to-switch between each vendor validated averaged between 50ms and 5 seconds. 6. Additional References The following reference documents can be obtained online at the Avaya Support website: Avaya P580 and P882 Gigabit Ethernet Switch User Guide Command Reference Guide for the Avaya P580, P882 Gigabit Ethernet Switches Avaya P333R Stackable Switch User Guide 19 of 20

20 Avaya and the Avaya Logo are trademarks of Avaya Inc. All trademarks identified by and are registered trademarks or trademarks, respectively, of Avaya Inc. All other trademarks are the property of their respective owners. The information provided in these Application Notes is subject to change without notice. The configurations, technical data, and recommendations provided in these Application Notes are believed to be accurate and dependable, but are presented without express or implied warranty. Users are responsible for their application of any products specified in these Application Notes. Please any questions or comments pertaining to these Application Notes along with the full title name and filename, located in the lower right corner, directly to the Avaya Solution & Interoperability Test Lab at 20 of 20