@tantony No there is no disadvantage, it just depends on your network design. If you are connecting to downstream switches that also support dot1q trunking and then break out different VLANs on different access ports, then you're all good. But if there was some reason to physically separate different switches for different VLANs, and configure the MX68 with per-port VLAN settings, then that's fine also, but obviously burns more ports and is not that scalable. But for 3 VLANs not a big deal. So the answer is "it depends" and you can do this either way, depends on what your requirements dictate, or what are the capabilities of the downstream devices.