Wills1
Contributor
Contributor

MAC flapping observed during a DRS vmotion

Hi,

We are randomnly seeing MAC flapping on our switches that conect our ESXi hosts. This flapping occurs when vmotion is invoked by DRS. However it only appears occassionally:

 

Dec 8 2020 02:26:40 RX01_H2_SwiStack_2x3x %%01FEI_COMM/4/hwMflpVlanLoopAlarm_active(l):CID=0x807f044e-alarmID=0x095e0012;MAC flapping detected, VlanId = 401, Original-Port = 10GE2/8/1, Flapping port = 10GE2/9/1,10GE2/5/2.Check the network connected to the interface learning a flapping MAC address : 0050-5683-9166.

All the ports connecting to the ESXi hosts are set to stp edge port enable and are trunking the varoius vlans.

For example the settings on a given ESXi host port are:

interface 10GE2/8/1
port link-type trunk
port trunk allow-pass vlan 2 4 40 101 192 234 401 to 403 509 900
stp edged-port enable

From a switch config perspective, is there something else that needs turning on/off?

From a vsphere perspective, are there some changes needed? This issue is not constant, it occurs randomly, but coincides exactly with the vmotioning of hosts. One of the virtual machines moving at the time (of which there are always 2) is using the vlan ID that flaps.

When this issue occurs, if I look in the hostd log of the ESXi host connected to the flapping port I see this:

 

2020-12-07T04:52:42.158Z error hostd[2100051] [Originator@6876 sub=VigorStatsProvider(000000a2af480030).GuestStats(469)] VigorCallback received fault: Disconnected from virtual machine.

This error only appears when the flap happens, so they are related.

Any thoughts?

 

 

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scott28tt
VMware Employee
VMware Employee

@Wills1 

Moderator: Moved to vSphere vNetwork Discussions


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