VLAN flapping between ports

[musthafa786]

Hi,

I am reciveing below logs, what should be the main causes ? , thanx.

switch-A#sh logging

Syslog logging: enabled (0 messages dropped, 1 messages rate-limited, 885 flushes, 0 overruns, xml disabled, filtering disabled)

    Console logging: level debugging, 50539 messages logged, xml disabled,

                     filtering disabled

    Monitor logging: level debugging, 0 messages logged, xml disabled,

                     filtering disabled

    Buffer logging: level debugging, 47828 messages logged, xml disabled,

                    filtering disabled

    Exception Logging: size (4096 bytes)

    Count and timestamp logging messages: disabled

    File logging: disabled

    Trap logging: level informational, 47984 message lines logged

Log Buffer (4096 bytes):

ween port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi6/0/44 and port Gi5/0/46

18w2d: %SW_MATM-4-MACFLAP_NOTIF: Host 0012.950a.9952 in vlan 10 is flapping between port Gi5/0/46 and port Gi6/0/44

[InayathUlla Sharieff · Accepted solution]

Hi Mohammed,

Error Message    SW_MATM-4-MACFLAP_NOTIF: Host [enet] in [chars] [dec] is flapping

between port [chars] and port [chars]

Recommended Action    The switch found the traffic from the specified host flapping

between the specified ports. [enet] is the host MAC address, [chars] [dec] is the switch

ID, the first and second [chars] are the ports between which the host traffic is flapping.

Recommended Action    Check the network switches for misconfigurations that might cause a

data-forwarding loop.

Further more I would like to add:

I have checked the outputs and I can see that there is only I mac addressbthat is causing the problem, i.e 0012.950a.9952, could you please trace this mac address and see if it is seen within the switch or it is being learnt

across the switch.

I can also see that the port channel is connected to the server, we could

get the error message if the NIC teaming is not done correctly.

NIC teaming allows users to group two or more physical NICs into a single

logical network device called a bond. Once a logical NIC is configured, the

virtual machine is notaware of the underlying physical NICs. Packets sent to

the logical NIC are dispatched toone of the physical NICs in the bond and

packets arriving at any of the physical NICs areautomatically directed to

the appropriate logical NIC.

If one of the underlying physical NICs is broken or its cable has been

unplugged, server  will detect the fault condition and automatically move

traffic to another NIC in the bond. This capability eliminates a single

point of failure for any one physical NIC and makes the overall network

connection fault-tolerant.

Hope this helps.

Regards

Inayath