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Cisco Bug: CSCup86496 - unicast ARP replies not destined to 3850 are forwarded to ARP module

Last Modified

Sep 14, 2019

Products (1)

  • Cisco Catalyst 3850 Series Switches

Known Affected Releases


Description (partial)

Cu migrated 3750 switches to 3850 switches. and they use NAC for security. 
The problem occurred with 3850 due to abnormal ARP table update.

Symptom:In 3850, we see that even the unicast ARP replies which are not destined to this box being forwarded to ARP module which will then learn and update the Src MAC for Src IP address which is creating an issue

Conditions:when the 3850 gets ARP replies which are not destined to this box
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