Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.112.0P1 - Page 992
Troubleshooting VLT
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Troubleshooting VLT To help troubleshoot different VLT issues that may occur, use the following information. NOTE: For information on VLT Failure mode timing and its impact, contact your Dell Networking representative. Table 105. Troubleshooting VLT Description Bandwidth monitoring Domain ID mismatch Behavior at Peer Up A syslog error message and an SNMP trap is generated when the VLTi bandwidth usage goes above the 80% threshold and when it drops below 80%. The VLT peer does not boot up. The VLTi is forced to a down state. Behavior During Run Time A syslog error message and an SNMP trap is generated when the VLTi bandwidth usage goes above its threshold. The VLT peer does not boot up. The VLTi is forced to a down state. Action to Take Depending on the traffic that is received, the traffic can be offloaded inVLTi. Verify the domain ID matches on both VLT peers. A syslog error message and an A syslog error message and an SNMP trap are generated. SNMP trap are generated. Dell Networking OS Version mismatch A syslog error message is generated. Remote VLT port channel status N/A Spanning tree mismatch at global level All VLT port channels go down on both VLT peers. A syslog error message is generated. A syslog error message is generated. N/A No traffic is passed on the port channels. A one-time informational syslog message is generated. Follow the correct upgrade procedure for the unit with the mismatched Dell Networking OS version. Use the show vlt detail and show vlt brief commands to view the VLT port channel status information. During run time, a loop may occur as long as the mismatch lasts. To resolve, enable RSTP on both VLT peers. Spanning tree mismatch at port level System MAC mismatch Unit ID mismatch A syslog error message is generated. A syslog error message and an SNMP trap are generated. The VLT peer does not boot up. The VLTi is forced to a down state. A syslog error message is generated. A one-time informational syslog message is generated. A syslog error message and an SNMP trap are generated. The VLT peer does not boot up. The VLTi is forced to a down state. A syslog error message is generated. Correct the spanning tree configuration on the ports. Verify that the unit ID of VLT peers is not the same on both units and that the MAC address is the same on both units. Verify the unit ID is correct on both VLT peers. Unit ID numbers must be sequential on peer units; for example, if Peer 1 is unit ID "0", Peer 2 unit ID must be "1'. Version ID mismatch A syslog error message and an SNMP trap are generated. A syslog error message and an SNMP trap are generated. Verify the Dell Networking OS software versions on the VLT peers is compatible. For more 992 Virtual Link Trunking (VLT)
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