I found out it only happens when the output is on the screen. When capturing to pcap file it usually remains on for the duration given. I also have another issue with the packet capture tool on switches.   Since the packet capture is done from the dashboard, I suspect the capture is made after the frame has been processed by the ingress asic.  Since even with tagged or untagged VLAN assignments all captures from the dashboard have an 802.1Q tag assigned which does not always correspond to the incoming frame in a port.  So sometimes it's difficult to troubleshoot if a voice VLAN is getting the correct input from a phone or a server is tagging it's traffic as it should. ... View more