Troubleshooting Bpdu Guard; Bpdu Guard Troubleshooting Commands - Cisco Nexus 1000V Troubleshooting Manual

Troubleshooting BPDU Guard

Enabling UUFB
To enable UUFB, enter these configuration commands, one on each line. At the end, press Cntl-Z.
switch# configure terminal
switch (config)# uufb enable
switch (config)#
This configuration conceals the requests from the non-NLB ports and allows the system to function as
it expected.
Disabling UUFB for VMs That Use Dynamic MAC Addresses
Issues might occur for VMs that use dynamic MAC addresses, other than those MAC addresses assigned
by VMware. For ports that host these types of VMs, disable UUFB. To disable UUFB, enter the
following commands:
switch(config)# int veth3
switch(config-if)# switchport uufb disable
switch(config-if)#
Troubleshooting BPDU Guard
BPDU Guard is one of the Spanning Tree Protocol (STP) enhancements. This feature enhances switch
network reliability, manageability, and security. It prevent loops and broadcast radiation. We recommend
that you enable BPDU guard on access ports so that any end user devices on these ports that have BPDU
guard enabled cannot influence the topology. Any malfunctioning device connected to a virtual Ethernet
port can flood the Layer 2 network with unwanted BPDUs and causes STP to break down. When you
enable BPDU guard on the access-ports, it shuts down the port in the event that it receives a BPDU. To
bring up a port disabled by BDPU guard, you must remove the device from the network and then restart
the port by entering the shut/no shut command.

BPDU Guard Troubleshooting Commands

You can use the commands in this section to troubleshoot problems related to the Layer 2 MAC address
configuration.
Command
show switch edition
show spanning-tree bpdu guard info
show run interface name
Cisco Nexus 1000V Troubleshooting Guide, Release 5.2(1)SV3(1.1)
12-14
Chapter 12 Layer 2 Switching
Purpose
Displays the license edition. You must
have the ADVANCED 3.0 license for
BPDU guard to be enabled in DAOX.
See Example 12-10 on page
Displays the switch edition and
license information.
See Example 12-11 on page
Displays the BPDU guard status on a
port profile.
See Example 12-12 on page
12-15.
12-15.
12-15.
OL-31593-01