If your clients get DHCP from the shop VLAN that means those clients are in the wrong VLAN and just get DHCP from the upstream shop VLAN. Your two VLANs that are terminated on your core switch should not be serviced by the shop DHCP server.  So you should check on which VLAN the MAC address of the client is coming from.  I'm pretty sure you have a VLAN hop issue in your network due to a native VLAN mismatch or just blending both shop and client VLANs together.   You can also use dashboard captures with filter 'port 67 or port 68' to see all the DHCP messages passing to a certain port on the switches. ... View more