switch not working on some host in same vlan

I had a weird scenario.
after installing some updates and restarting the VM's on hyper V.
i noticed that ALL workstations on a VLAN able to ping each other, All servers on the same VLAN able to ping each other.
all servers and workstations are able to ping each other excel TWO.
two servers couldn't ping any workstations, nor the opposite.
not sure why there two servers only.
we restarted everything, that did no fix the problem.
we restarted the switch, the problem was fixed.
while looking at the logs on the switch, i noticed some duplicate MAC addresses of the same host.
the switch is a cisco switch, i don't have much more to share, and it seems pretty odd, don't know where to start in my troubleshooting. any ideas ? brain storming with me can be helpful.
thank you
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Istvan KalmarHead of IT Security Division Commented:
Hi Da_Ch0sen

I think you copied the VM and you nned to change the MAC address of the secondary, ater that you claerd the switch MAC table it will be working.

Best regards,

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Da_Ch0senAuthor Commented:
I didn't copy the VM, those VM's restarted too many times before with same configurations.
Istvan KalmarHead of IT Security Division Commented:
Hi Da_Ch0sen,

I've advise to manually configure indendent MAC address all VM, and it will be working. what type of switch do you have?

Best regards,
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