Troubleshooting Stp; About Troubleshooting Stp; Initial Troubleshooting Stp Checklist - Cisco Nexus 9000 Series Troubleshooting Manual

Troubleshooting STP

This chapter contains the following sections:
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About Troubleshooting STP

STP provides a loop-free network at the Layer 2 level. Layer 2 LAN ports send and receive STP frames at
regular intervals. Network devices do not forward these frames but use the frames to construct a loop-free
path. For more information on Layer 2, see the Cisco Nexus 9000 Series Layer 2 Configuration Guide.

Initial Troubleshooting STP Checklist

Troubleshooting an STP problem involves gathering information about the configuration and connectivity of
individual devices and the entire network.
Begin troubleshooting STP issues by checking the following issues first:
Checklist
Verify the type of spanning tree configured on your device.
Verify the network topology including all interconnected ports and switches. Identify all
redundant paths on the network and verify that the redundant paths are blocking.
About Troubleshooting STP, page 55
Initial Troubleshooting STP Checklist, page 55
Troubleshooting STP Data Loops, page 56
Troubleshooting Excessive Packet Flooding, page 59
Troubleshooting Convergence Time Issues, page 60
Securing the Network Against Forwarding Loops, page 60
C H A P T E R
Cisco Nexus 9000 Series NX-OS Troubleshooting Guide, Release 7.x
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