Explanation This is the most likely cause of preventing the users from accessing the application server because a VLAN is a logical segmentation of a network that isolates traffic based on certain criteria. If the human resources department and the application server are on different VLANs, they will not be able to communicate with each other unless there is a router or a switch that can route between VLANs. References: https://www.cisco.com/c/en/us/support/docs/lan-switching/inter-vlan-routing/41860-howto-L3-intervlanrouting.h