mac flapping

[RIYAJOSHI]

Anyone can help me to resolve this issue below are the logs on my l3(CAT9K_IOSXE) 

Logs:-

May 26 23:17:29: %SW_MATM-4-MACFLAP_NOTIF: Host 0015.5d97.f616 in vlan 10 is fl apping between port Te1/0/19 and port Te1/0/24
May 26 23:17:40: %SW_MATM-4-MACFLAP_NOTIF: Host 0015.5d97.f616 in vlan 10 is fl apping between port Te1/0/19 and port Te1/0/24

[Francesco Molino]

Hi
What is connected on both ports ?
And can you share the configuration of these ports?

[RIYAJOSHI]

From these two Tengig Trunk ports two access switches are connected.

L3 # sh run interface Te1/0/19
Building configuration...

Current configuration : 211 bytes
!
interface TenGigabitEthernet1/0/19
description AccessSW2 Ten1/1/1
switchport trunk allowed vlan X1,X2,X3,10
switchport mode trunk
switchport nonegotiate
spanning-tree guard root
end

L3 #sh run interface Te1/0/24
Building configuration...

Current configuration : 219 bytes
!
interface TenGigabitEthernet1/0/24
description AccessSW1 Ten1/1/1
switchport trunk allowed vlan X1,X2,X3,10
switchport mode trunk
switchport nonegotiate
spanning-tree guard root
end

[Sergiu.Daniluk]

Hi @RIYAJOSHI 

Next step is to go to the AccessSW1 and AccessSW2 look again for the respective MAC moves logs. You will find out which interfaces are the source of the mac moves. Usually this happens when there is an incorrect config between a server and switch(s). For example: Server is dual-homed to two different switches with active/active links, and the switches are not using a virtualization protocol (VSS, stacking, vPC) to act as a single virtual switch.

Other issue might be a loop in the network, or a bug in the switchs software which leads to packets being looped.

Hope it helps.

Stay safe,

Sergiu

[Francesco Molino]

As @Sergiu.Daniluk said, you need to go on both switches and issue the command show mac add add xxxx.xxxx.xxxx (replace x by mac adresses) to see from where this mac is learned and figure out if it's a loop or a misconfiguration of multi homed device like server for example