Host Flapping

[Toss Leey]

Hi

I always get these messages on switche, if anyone faced this issue and how resolved:-

%SW_MATM-4-MACFLAP_NOTIF: Host xxxx.xxxx.xxxx in vlan 11 is flapping between port Po3 and port Gi1/0/19

%SW_MATM-4-MACFLAP_NOTIF: Host yyyy.yyyy.yyyy. in vlan 11 is flapping between port Po3 and port Gi1/0/31

+configuration for g1/0/19 and 31

interface range GigabitEthernet1/0/19, 31
 switchport access vlan 10
 switchport mode access
 switchport voice vlan 11
 spanning-tree portfast

+configuration for up-link

interface GigabitEthernet1/0/23
 switchport mode trunk
 channel-group 3 mode on
!
interface GigabitEthernet1/0/24
 switchport mode trunk
 channel-group 3 mode on

Thank you

[johnd2310]

Hi

What is connected  to g1/0/19 and 31? Check that whatever is connected to these ports is connected properly.

Thanks

John

[Nithyanandan P]

Generally, If Frame reaches switch, it learns Source MAC, VLAN, Port and adds it in Table. Here VLAN 11 is for Voice so it should be connected with Voice IP Phone.

Po3 is switch uplink and it is learning same MAC address and it may be reason if anyone moved Voice IP Phone from this switch to any other switch, it happens. If it is happening more frequently, switch CPU will go high and will create a problem for production network.