VLAN support is a feature typically found in managed switches, not unmanaged switches. VLANs allow network administrators to segregate traffic for security and to improve traffic management. While all the other features are valuable, an unmanaged switch may provide Quality of Service (QoS) and SNMP, but not VLAN configuration as it lacks the capability for advanced settings management. Port mirroring is typically a feature configured on managed switches for the purpose of network monitoring and is not present on unmanaged switches.