Symptom

Below log observed while Total Mac Address In Use does not reach its limits. "%PLATFORM_MATM-4-QUEUE_OVERLIMIT: MATM dropped learn cache batch messages as queue limit has reached" BB2-3850-CAMPUS-3# Jan 27 19:06:33 India: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: ciscocts] [Source: LOCAL] [localport: 0] at 19:06:33 India Mon Jan 27 2020 BB2-3850-CAMPUS-3#show mac add coun summary Total Dynamic Address Count : 1924 Total Static Address Count : 1 Total Mac Address In Use : 1925 Total Mac Address Space Available: 30843

Conditions

Workaround

Further Problem Description

when user have 2k Mac addresses, and system reload, all the Mac addresses will be pushed to IOSd in say less than 500ms. IOSd cannot process all of them, this causes the IOSd to drop the learn entries. But fed has recovery mechanism where it resends the addresses for IOSd to install. As fed has already installed these entries, it will not cause flooding. So we are safe, only difference here is that IOSd will process little slower and install in all stack