Host [MAC] vlan [x] is flapping between port [x/x/x] and port [x/x/x]

[LCMC]

Hi all, I have two switches connected in cross-3750X stack into a single SW 6500., But I get the following error appears.

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

What can i do?
Thank you very much¡¡.

[Leo Laohoo]

What is this machine with a MAC address of "0012.950a.9952"?  What is the configuration for ports Gi5/0/46 & Gi6/0/44?  

This error message is common when etherchannel is not configured properly at either ends.

[LCMC]

forget the MAC this is a example.... on the attahcment you can see the error... yes maybe is a problem with etherchannel. 

SW6500-------------SW3750X(1)

            -------------SW3750(2)

is conexion among one 6500 and two 3705X. 

when i create the portchannel this issue appear.

[Leo Laohoo]

Are the two 3750 in a stack?

[Walter Astori]

The configuration on the port channel is that all the port must be with the equal configuration :

For example :

interface Port-channel1
 description IDC-TO6500 - 192.168.0.12
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,54,136,192,432
 switchport mode trunk
 speed 100
 duplex full

interface GigabitEthernet1/0/1
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,54,136,192,432
 switchport mode trunk
 speed 100
 duplex full
 channel-protocol lacp
 channel-group 1 mode active
!
interface GigabitEthernet1/0/2
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,54,136,192,432
 switchport mode trunk
 speed 100
 duplex full
 channel-protocol lacp
 channel-group 1 mode active
!
 

The same configuration is on the 3750 :

interface Port-channel1
 description IDC-TO3750 - 192.168.0.12
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,54,136,192,432
 switchport mode trunk
 speed 100
 duplex full

interface GigabitEthernet1/0/1
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,54,136,192,432
 switchport mode trunk
 speed 100
 duplex full
 channel-protocol lacp
 channel-group 1 mode active
!
interface GigabitEthernet1/0/2
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,54,136,192,432
 switchport mode trunk
 speed 100
 duplex full
 channel-protocol lacp
 channel-group 1 mode active
!

[LCMC]

yes, they are.¡

[paul driver]

Hello

If you know your physical topology then somewhere between you switches you have a loop

show spanning-tree vlan 10

This will show you what ports are forwarding and its is also where you should discover what port shouldn't be in a forwarding state which is causing the stp loop

res

Paul