VLAN XXX is flapping between port Gx/x/x

[JamesRobertson]

Hello everyone,

Here is the scenario.  I have a HDMI TX and Multiple HDMI RX receivers.  These devices can be configured to use UDP packets from the TX box to multiple RX receivers on the same Vlan displaying the same image for my guests.  However I am always receiving the

Host 000b.7800.6002 in vlan 192 is flapping between port Gi1/0/34 and port Gi1/0/35

Host 000b.7800.6002 in vlan 192 is flapping between port Gi1/0/36 and port Gi1/0/34

interface GigabitEthernet1/0/34
description Wall Displays
switchport access vlan 192
switchport mode access
spanning-tree portfast

Does anyone know how I can stop the annoying messages from filling up my logs.  The devices are working as specified.

[Ruben Cocheno]

Last time something similar happened was related to a flapping port in one of the switches, spanning-tree was reconverging and i was getting a ton of those messages. Perhaps you can ignore/archive those messages on your syslog, keeping one single point of control.

[balaji.bandi]

what is the device connection port 35 ?

by the way, what is this product and model information to suggest more accurate.

[Leo Laohoo]

What downstream clients are connected to ports 34, 35 & 36? 

[JamesRobertson]

Thank you for the responses.

Sorry for not posting the hardware 
Cisco Catalyst 3850 WS-C3850-48P sw:16.12.3a stack config.
End devices are NTI ST-IPHD-LC, TX and RX HDMI Extenders.

Port 33 is the Transmitter end device

Ports 34,35,36 are the receiver end devices

[Leo Laohoo]

Hmmmm ... Can you do a COLD reboot?  

NOTE:  Cold reboot is pulling all the power cables of the switch.  

[JamesRobertson]

Yes I have tried a cold boot as well.

[JamesRobertson]

Well found the problem.  These HDMI Extenders were definitely cheep.  All RX devices use the same MAC Address and so does the TX devices.  Thank goodness they actually were programmable at the interface as that cleared up all my issues.