I have an issue recently that a PC connected on VLAN106 (SALES) kept getting a DHCP leased IP address from a DHCP server on VLAN 100 (TECH). I do not have this issue with any other VLANs so I am thinking right after the sales folks made some move they have accidentally crossed the two VLANS and created a switching loop or bridged the two VLANs. How do I go about troubleshooting this issue? Please let me know if you guys have questions or need further clarification. Thank you all in advanced.