05-14-2017 10:23 PM - edited 03-08-2019 10:34 AM
im getting these messages from a customer 3750x two stack switches , can anyone please tell me what does they mean and how to fix them?
128016: .May 14 07:18:51.561 KWT: %SW_MATM-4-MACFLAP_NOTIF: Host 7c95.f32e.aeb7 in vlan 17 is flapping between port Te1/1/2 and port Te1/1/1
128026: .May 14 07:23:03.037 KWT: %PLATFORM_STACKPOWER-4-REDUNDANCY_LOSS: Switch 2's power stack lost redundancy and is now operating in power sharing mode
05-15-2017 12:30 AM
128016: .May 14 07:18:51.561 KWT: %SW_MATM-4-MACFLAP_NOTIF: Host 7c95.f32e.aeb7 in vlan 17 is flapping between port Te1/1/2 and port Te1/1/1
These can be legitimate notifications if you have wireless users moving between devices at access layer and macs are being learnt in more than once , you could trace the macs make sure its legitimate traffic or turn it off either
no mac-address-table notification mac-move
Look at this doc for the 2nd issue the alert is there an what you can try to fix it
https://supportforums.cisco.com/document/72421/troubleshooting-tips-3750x-stack-power-feature
05-15-2017 10:15 PM
but what if this isnt a wireless user? doesnt this message means there is a loop in the network as the mac is learned from two different ports??? or a spanning tree issue???
05-16-2017 12:19 AM
so that's the thing with mac move notification it can be a loop but you should see that in cpu if its spiking but it can also be legitimate users , it doesn't even have to be wireless , like a scenario if you have 5 sales guys having a meeting in building A all connected to access switch 1 there macs are recorded as coming in through that switch and up to say your core vss switches but then they get up and all move to building B and then connect to switch 2 within 5 minutes , once there macs are still in the CAM table within the 5 minutes it will register a mac move as the CAM table already sees there macs after being learned in one access switch and now a second switch , scenarios like that cause mac moves as well and the longer your CAM table is set to store them over the default the more you may se them
that's why I was saying check the macs see what they are , trace them to a user system or device see what it is then you will know more , checking for a loop is easy enough check your stp isn't constantly involved in changes it should be steady enough
The fact these are between two 10 gigs links I thought they may be the core interconnects , at some stage the mac may have been learnt through both switches but its all down to the mac and what its doing , if you have a loop your cpu will keep spiking and continue to get high and show stp as an issue in logs and in cpu along with mac move
That's why you have the ability to turn off mac move as its not always an issue and can just cause logging flooding issues depending on your design of your network
show spanning-tree detail | inc ieee|occurr|from|is exec
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