Preview Tool

Cisco Bug: CSCvv82819 - Manually configured MAC address is programmed in hardware when interface is admin down

Last Modified

Oct 14, 2020

Products (1)

  • Cisco Catalyst 9600 Series Switches

Known Affected Releases


Description (partial)

A Catalyst 9k switch may install a static mac address entry for the SVI hw and/or bia address despite the SVI being admin-down. 

In this scenario, with no active L3 interface we would expect the mac not to be installed until the SVI is brought online and becomes active. This static entry caused the mac to not be learned dynamically if it lives elsewhere in the network.

First seen on Cat9600 switches running 17.3.1, this may also be seen on other Cat9k series switches and impacts 16.12.4 as well.

To run into this, you must have a user defined mac address configured on the SVI and either configure the mac after the interface is admin down, or reload the switch with this config already in place.
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.