Error : 5w2d: %SW_MATM-4-MACFLAP_NOTIF: flapping

[bruce.thornton]

Getting the following log error message, my software ver is:

Base Ethernet MAC Address          : b4:de:31:74:55:00
Motherboard Assembly Number        : 73-15901-06
Motherboard Serial Number          : FDO2146062P
Model Revision Number              : Q0
Motherboard Revision Number        : B0
Model Number                       : WS-C3650-48PS
System Serial Number               : FDO2146Q0GA


Switch Ports Model              SW Version        SW Image              Mode
------ ----- -----              ----------        ----------            ----
*    1 52    WS-C3650-48PS      16.3.5b           CAT3K_CAA-UNIVERSALK9 INSTALL

The flapping messages are:

:56.092: %SW_MATM-4-MACFLAP_NOTIF: Host 7070.0d98.40cf in vlan 677 is flapping between port Gi1/0/2 and port Gi1/1/2
Dec 10 15:29:03.727: %SW_MATM-4-MACFLAP_NOTIF: Host 009d.6b0c.5987 in vlan 677 is flapping between port Gi1/1/2 and port Gi1/1/3
Dec 10 15:34:04.505: %SW_MATM-4-MACFLAP_NOTIF: Host fc18.3c74.c9a5 in vlan 677 is flapping between port Gi1/1/2 and port Gi1/0/2
Dec 10 15:35:01.547: %SW_MATM-4-MACFLAP_NOTIF: Host 5caf.062b.bdb5 in vlan 677 is flapping between port Gi1/0/2 and port Gi1/1/2
Dec 10 15:36:47.316: %SW_MATM-4-MACFLAP_NOTIF: Host fc18.3c74.c9a5 in vlan 910 is flapping between port Gi1/0/3 and port Gi1/1/3
Dec 10 15:41:23.364: %SW_MATM-4-MACFLAP_NOTIF: Host 245b.a738.a9f8 in vlan 677 is flapping between port Gi1/0/2 and port Gi1/0/3
Dec 10 15:42:56.021: %SW_MATM-4-MACFLAP_NOTIF: Host 245b.a738.a9f8 in vlan 910 is flapping between port Gi1/1/2 and port Gi1/0/3
Dec 10 15:45:33.905: %SW_MATM-4-MACFLAP_NOTIF: Host a056.f38e.8398 in vlan 677 is flapping between port Gi1/0/2 and port Gi1/1/3
Dec 10 15:52:21.481: %SW_MATM-4-MACFLAP_NOTIF: Host 4098.ad73.9957 in vlan 910 is flapping between port Gi1/0/1 and port Gi1/1/3
Dec 10 09:56:55.859: %SYS-5-CONFIG_I: Configured from console by thornbt on vty0 (10.11.216.215)
Dec 10 09:57:18.980: %SW_MATM-4-MACFLAP_NOTIF: Host d004.012d.3031 in vlan 910 is flapping between port Gi1/1/2 and port Gi1/1/3
Dec 10 09:57:25.475: %SW_MATM-4-MACFLAP_NOTIF: Host f895.ea30.e67e in vlan 910 is flapping between port Gi1/0/4 and port Gi1/0/2
Dec 10 09:57:33.909: %SYS-6-CLOCKUPDATE: System clock has been updated from 09:57:33 Central Mon Dec 10 2018 to 09:57:33 central Mon Dec 10 2018, configured from console by thornbt on vty0 (10.11.216.215).
Dec 10 09:58:00.741: %SYS-5-CONFIG_I: Configured from console by thornbt on vty0 (10.11.216.215)
Dec 10 10:04:28.820: %SW_MATM-4-MACFLAP_NOTIF: Host 645a.ed1f.4c50 in vlan 677 is flapping between port Gi1/1/3 and port Gi1/0/2
Dec 10 10:06:29.529: %SW_MATM-4-MACFLAP_NOTIF: Host 645a.ed1f.4c50 in vlan 910 is flapping between port Gi1/0/2 and port Gi1/0/4
Dec 10 10:07:36.050: %SW_MATM-4-MACFLAP_NOTIF: Host 5c8d.4ee1.bf2a in vlan 677 is flapping between port Gi1/1/3 and port Gi1/0/4
Dec 10 10:08:38.791: %SYS-5-CONFIG_I: Configured from console by thornbt on vty0 (10.11.216.215)
Dec 10 10:08:50.128: %SW_MATM-4-MACFLAP_NOTIF: Host 4491.60ef.2e3e in vlan 910 is flapping between port Gi1/0/5 and port Gi1/1/2
Dec 10 10:14:09.440: %SW_MATM-4-MACFLAP_NOTIF: Host f86f.c180.377c in vlan 910 is flapping between port Gi1/1/2 and port Gi1/0/4
Dec 10 10:15:10.632: %SW_MATM-4-MACFLAP_NOTIF: Host fcc2.de00.4fa4 in vlan 910 is flapping between port Gi1/0/3 and port Gi1/0/5
Dec 10 10:16:45.855: %SW_MATM-4-MACFLAP_NOTIF: Host a407.b6a5.5aa3 in vlan 910 is flapping between port Gi1/0/5 and port Gi1/1/2
Dec 10 10:17:43.382: %SW_MATM-4-MACFLAP_NOTIF: Host a408.ea75.5429 in vlan 910 is flapping between port Gi1/0/5 and port Gi1/1/3
Dec 10 10:32:29.091: %SW_MATM-4-MACFLAP_NOTIF: Host d88f.76b4.12dc in vlan 910 is flapping between port Gi1/1/3 and port Gi1/0/2

[Daniele Giordano]

Hi.

Mac address flapping is symptom of network loop.
Is spanning tree enable on your switch?
If no, can you try to enable STP and check for ports blocked by spanning tree?
Investigate for the same thing also on the devices connected to port G1/0/1, G1/0/2, G1/0/4, G1/1/2, G1/1/3.
Checking on every devices and switched you can identify where the flapping is generated.

Regards.

[paul driver]

Hello

Check you cabling on these ports. also what is attached to them, if they are access ports make sure you dont have stp disabled them such via bpdufilter, if there are trunks port make sure portfast isn't enabled

If there are switches attached to these ports them make sure they are not being looped back into the network.