Hi, as much as i understood from this article earlier, and my working on MX since i had an answer. it will not work. To have a L3 Switch with Vlan interfaces configured on, and to have the MX unit after this switch. this setting will lead you to the problem of having to configure the clients manually to the desired group you need these clients to be a member of. if you have the same scenario that i had earlier. that i had a guests vlan, and wanted to make sure that the any one connected to the Guests vlan to automatically been assigned to the Guests group. then i removed the VLAN interface from the L3 switch and passed the Guests VLAN to the MX -after i created the same VLAN on the MX Unit- and configured the VLAN interface on the MX unit. also applied DHCP from MX to this VLAN. then it was solved. so the Staff VLANs were kept on the L3 switch, and the Guests VLAN interface was moved to the MX unit rather that the L3 Switch. Kind Regards ... View more