NEC IP8800/S2400 Series Troubleshooting Manual

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NEC IP8800/S2400 Series Troubleshooting Manual Manual pdf 103 page image

3. Troubleshooting Functional Failures in Operation41bridge for each MST instance for route bridge, when checking the route bridge.Table 3-14: Spanning Tree Failure Analysis Method3.5.3 Failures on Using Ring ProtocolThis subsection describes Autonomous Extensible Ring Protocol failure.The Autonomous Extensible Ring Protocol is redundant protocol on the layer 2 network for ring topology, refer to it as"Ring Protocol" hereafter.When the communication is disabled during Ring Protocol operation, follow the analysis flow to identify the symptomNo. Troubleshooting Steps and Command Action1 Execute the show spanning-treecommand for the failed spanning tree andcheck the protocol status of the spanning tree.If shown as Enable, go to No. 2.When tree information is not displayed while Ring Protocol and PVST+ both arein use, go to No.7.If shown as Disable, the spanning tree is suspended. Check the configuration.Ring Protocol and multiple spanning tree both are used, go to No.8.Check to see if the number of PVST+s is within the conditions of accommodation.2 Execute the show spanning-treecommand for the failed spanning tree andcheck the bridge identifier of the route bridgefor the spanning tree.Go to No. 3 if the bridge identifier of the route bridge complies with the networkconfiguration.Check the network configuration and configuration if the bridge identifier of theroute bridge does not comply with the network configuration.3 Execute the show spanning-treecommand for the failed spanning tree andcheck the port status and the port role of thespanning tree.Go to No. 4 if the spanning tree port status and port role comply with the networkconfiguration.When the systems before Ver10.6 is used:If the port status of the port for which the loop guard function is defined isBlocking or Discarding, check to see if the port is a designated port. If the port isa designated port, delete the setting of the loop guard function.If the spanning tree port status and port role do not comply with the networkconfiguration, check the neighboring system status and configuration.4 Execute the show spanning-treestatistics command for the failedspanning tree and check BPDU sending andreceiving on the failed port.Check the BPDU sending/receiving counter.[Root port]Go to No. 5 if the BPDU receiving counter has been incremented.If not so, BPDU may have been discarded by filtering, or BPDU may havebeen discarded through bandwidth monitoring, discarding control, or shaperof the QoS control. See "3.23.1 Checking Filtering/QoS Setting Information"to check for it. If no problem is found, check the neighboring system.[Designated port]Go to No. 5 if the BPDU sending counter has been incremented. Otherwise,see "3.4 Network Interface Communication Failure."5 Execute the show spanning-treecommand for the failed spanning tree with"detail" parameter specified, and check thereceived BPDU bridge identifier.Confirm that the received BPDU route bridge identifier and sending bridgeidentifier comply with the network configuration. Otherwise, check theneighboring system status.6 Check to see if the maximum number offailed spanning trees is within theaccommodating conditions.Set up the number within the range of the accommodating conditions. For theaccommodating conditions, see "Configuration Settings."7 Check to see if vlan-mapping is applied tothe single VLAN that is to operate withPVST+.If vlan-mapping of Ring Protocol is not applied to the target VLAN, configure it.In addition, if multiple VLANs are applied to the vlan-mapping, review thevlan-mapping and change it to a single VLAN.8 Check to see if the vlan-mapping of VLANsto be operated with MST instances is thesame as that of Ring Protocol.If vlan-mapping of Ring Protocol is not applied to the target VLAN, adjust it tomatch the configuration of VLANs with multiple spanning tree enabled.