06-13-2018 07:39 PM - edited 03-08-2019 03:21 PM
Just want to ask assistance regarding to this log message on our cisco switch. Is this a layer 2 looping issue. how can I prevent this or fix this?
Jun 14 2018 07:31:37.821 PHT: %SW_MATM-4-MACFLAP_NOTIF: Host c8d7.19c2.a4e4 in vlan 8 is flapping between port Gi0/7 and port Gi0/8
Jun 14 2018 09:32:21.113 PHT: %SW_MATM-4-MACFLAP_NOTIF: Host b88a.60d4.92e8 in vlan 8 is flapping between port Gi0/7 and port Gi0/8
nhcph036#show run interface gigabitEthernet 0/7
Building configuration...
Current configuration : 233 bytes
!
interface GigabitEthernet0/7
description connected to - R600 RUCKUS AP
switchport trunk allowed vlan 1,8,10,12,256
switchport trunk native vlan 256
switchport mode trunk
switchport nonegotiate
no power efficient-ethernet
end
nhcph036#show run interface gigabitEthernet 0/8
Building configuration...
Current configuration : 163 bytes
!
interface GigabitEthernet0/8
description CONNECTED TO NHCPH014 SWITCH
switchport trunk allowed vlan 1,8,10,12,256
switchport mode trunk
switchport nonegotiate
end
06-13-2018 08:33 PM
Hi Mate,
you'd find a lot of discussions in regards to this matter in the forum.
MACFLAP notifications basically indicate that the MAC address is moved from one port to the other within a short time.
In your case, it looks like a wireless client roamed from an access point attached to the port Gi0/7 to another access point. This behaviour is normal for wireless
you should be able to observe the behaviour with #show mac-address-table address **MAC**
Regards,
Prabath
06-13-2018 08:38 PM
Hi,
What devices are using those mac addresses? Are they wireless devices? If they are wireless devices, it could be that they are bouncing from between access points. If they are not wireless devices, they there could be a layer 2 loop.
If it is a layer 2 issue you could enable bpdu guard on all ports that should not be connected to a switch.
Thanks
John
06-13-2018 10:32 PM
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