D-Link DGS-3130 User Manual - Page 304

DGS-3130 Series Layer 3 Stackable Managed Switch Web UI Reference Guide Figure 9-69 RADIUS Authentication Server Conditions and Limitations  If the client is utilizing DHCP to attain an IP address, the authenticating VLAN must provide a DHCP server or a DHCP relay function so that client may obtain an IP address.  Certain functions exist on the Switch that will filter HTTP packets, such as the ACL function. The user needs to be very careful when setting filter functions for the target VLAN, so that these HTTP packets are not denied by the Switch.  If a RADIUS server is to be used for authentication, the user must first establish a RADIUS Server with the appropriate parameters, including the target VLAN, before enabling Web Authentication on the Switch. 294