Operation Manual – PortalH3C S7500E Series Ethernet Switches Chapter 1 Portal Configuration1-5From this point of view, the difference between these two authentication modes lies inwhether or not a Layer 3 forwarding device can be present between the authenticationclient and the access device. The former supports Layer 3 forwarding devices, whilethe latter does not.z User identifierIn Layer 3 authentication mode, a client is uniquely identified by an IP address. This isbecause the mode supports Layer 3 forwarding devices between the authenticationclient and the access device but the access device does not learn the MAC address ofthe authentication client. In non-Layer 3 authentication mode, a client is uniquelyidentified by the combination of its IP address and MAC address because the accessdevice can learn the MAC address of the authentication client.Due to the above differences, when the MAC address of an authentication clientremains the same but the IP address changes, a new portal authentication will betriggered in Layer-3 authentication mode but will not be triggered in non-Layer 3authentication mode. In non-Layer 3 authentication mode, a new portal authenticationwill be triggered only when both the MAC and IP address of the authentication client arechanged.1.1.5 Portal Authentication ProcessDirect authentication and Layer 3 authentication share the same authenticationprocess. When it comes to re-DHCP authentication, the process is different for thepresence of two address allocation procedures.I. Direct authentication/Layer 3 authentication processFigure 1-2 Direct authentication/Layer 3 authentication processFor portal authentication, the direct authentication/Layer 3 authentication process is asfollows:1) A portal user initiates an authentication request through HTTP. When HTTPpackets arrive at the access device, the access device allows those destined for
