D-Link DGS-3620-52P Web UI Reference Guide - Page 353

xStack® DGS-3620 Series Layer 3 Managed Stackable Gigabit Switch Web UI Reference Guide MAC-based Access Control Authentication State This window displays MAC-based access control Authentication State information. To view this window, click Security > MAC-based Access Control (MAC) > MAC-based Access Control Authentication State as shown below: Figure 8-28 MAC-based Access Control Authentication State window The fields that can be configured are described below: Parameter Description Port List Enter a list of ports. Click the Find button to locate a specific entry based on the information entered. Click the Clear by Port button to clear all the information linked to the port number entered. Click the View All Hosts button to display all the existing hosts. Click the Clear All hosts button to clear out all the existing hosts. Web-based Access Control (WAC) Web-based Authentication Login is a feature designed to authenticate a user when the user is trying to access the Internet via the Switch. The authentication process uses the HTTP or HTTPS protocol. The Switch enters the authenticating stage when users attempt to browse Web pages (e.g., http://www.dlink.com) through a Web browser. When the Switch detects HTTP or HTTPS packets and this port is un-authenticated, the Switch will launch a popup user name and password window to query users. Users are not able to access the Internet until the authentication process is passed. The Switch can be the authentication server itself and do the authentication based on a local database, or be a RADIUS client and perform the authentication process via the RADIUS protocol with a remote RADIUS server. The client user initiates the authentication process of WAC by attempting to gain Web access. D-Link's implementation of WAC uses a virtual IP that is exclusively used by the WAC function and is not known by any other modules of the Switch. In fact, to avoid affecting a Switch's other features, WAC will only use a virtual IP address to communicate with hosts. Thus, all authentication requests must be sent to a virtual IP address but not to the IP address of the Switch's physical interface. Virtual IP works like this, when a host PC communicates with the WAC Switch through a virtual IP, the virtual IP is transformed into the physical IPIF (IP interface) address of the Switch to make the communication possible. The host PC and other servers' IP configurations do not depend on the virtual IP of WAC. The virtual IP does not respond to any ICMP packets or ARP requests, which means it is not allowed to configure a virtual IP on the same subnet as the Switch's IPIF (IP interface) or the same subnet as the host PCs' subnet. As all packets to a virtual IP from authenticated and authenticating hosts will be trapped to the Switch's CPU, if the virtual IP is the same as other servers or PCs, the hosts on the WAC-enabled ports cannot communicate with the server or PC which really own the IP address. If the hosts need to access the server or PC, the virtual IP cannot be the same as the one of the server or PC. If a host PC uses a proxy to access the Web, to make the authentication work properly the user of the PC should add the virtual IP to the exception of the proxy configuration. Whether or not a virtual IP is specified, users can access the WAC pages through the Switch's system IP. When a virtual IP is not specified, the authenticating Web request will be redirected to the Switch's system IP. 343