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Cisco Bug: CSCun42922 - Nexus 3500: Input Discards due to STP Blocking or VLAN Disallowed

Last Modified

Nov 27, 2020

Products (2)

  • CiscoPro Workgroup EtherSwitch Software
  • Cisco Nexus 3548 Switch

Known Affected Releases


Description (partial)

Input discards under "show interface Eth x/y" incrementing on the Nexus 3500.

Also, the PORT_EXCEPTION_ICBL_PKT_DROP counter reported by "show hardware internal statistics device mac error port <port#>" command also increments.


Ingress traffic on a port for a VLAN in STP blocking state.


Ingress traffic on a port for a VLAN not in the trunk allowed list.

Related Community Discussions

CSCuo57455 - Nexus 3000 Input Discards due to STP Blocking or VLAN Disallowed when Juniper SRX650 Cluster Control Link port Connected
Hello, I have two Juniper SRX650 FW devices and they are currently configured in Cluster mode. At the moment their cluster Control Link and Data fabric Interlink are connected to a Cat 2960G switch with jumbo frames enabled. But I want to move the cluster Control Link and Data Interlink port connections to a Nexus 3064 switch. When I connect the Cluster Control Link to an access port on the Nexus 3K, the Juniper FW cluster goes down. When I reconnect the Control Link back to cat 2960G the FW cluster ...
Latest activity: May 10, 2018
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