It's up to the device to tag it's own traffic with the voice VLAN. The only thing the Meraki switch will do is periodically send CDP and LLDP messages detailing the voice VLAN in use.   You can perfectly capture this using following capture filter: ether host 01:80:c2:00:00:0e or ether host 01:00:0c:cc:cc:cc.   Documented here: https://documentation.meraki.com/MS/Port_and_VLAN_Configuration/Verifying_Voice_and_Data_VLAN_tags_with_LLDP_phones   So perhaps you'll have to check the device what it supports, static, cdp, lldp or both and setup accordingly. ... View more