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Protocols used for interaction between the client and local portal server
HTTP and Hypertext Transfer Protocol Secure (HTTPS) can be used for interaction between an
authentication client and an access device providing the local portal server function. If HTTP is used,
there are potential security problems because HTTP packets are transferred in plain text; if HTTPS is used,
secure data transmission is ensured because HTTPS packets are transferred in cipher text based on SSL.
Authentication page customization support
The local portal server function allows you to customize authentication pages. You can customize
authentication pages by editing the corresponding HTML files and then compress and save the files to the
storage medium of the device. A set of customized authentication pages consists of six authentication
pages—the logon page, the logon success page, the online page, the logoff success page, the logon
failure page, and the system busy page. A local portal server will push a corresponding authentication
page at each authentication phase. If you do not customize the authentication pages, the local portal
server will push the default authentication pages.
For the rules of customizing authentication pages, see "
Customizing authentication pages
."
Portal authentication modes
Portal authentication may work at Layer 2 or Layer 3 of the OSI model.
Layer 2 portal authentication
You can enable Layer 2 portal authentication on an access device’s Layer 2 ports that connect
authentication clients, so that only clients whose MAC addresses pass authentication can access the
external network. Only the local portal server provided by the access device supports Layer 2 portal
authentication.
Layer 2 portal authentication allows the authentication server to assign different VLANs according to user
authentication results so that access devices can thereby control user access to resources. After a client
passes authentication, the authentication server can assign an authorized VLAN to allow the user to
access the resources in the VLAN. If a client fails authentication, the authentication server can assign an
Auth-Fail VLAN. Layer 3 portal authentication does not support VLAN assignment.
Layer 3 portal authentication
You can enable Layer 3 authentication on an access device's Layer 3 interfaces that connect
authentication clients. Portal authentication performed on a Layer 3 interface can be direct authentication,
re-DHCP authentication, or cross-subnet authentication. In direct authentication and re-DHCP
authentication, no Layer-3 forwarding devices exist between the authentication client and the access
device. In cross-subnet authentication, Layer-3 forwarding devices may exist between the authentication
client and the access device.
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Direct authentication
Before authentication, a user manually configures a public IP address or directly obtains a public
IP address through DHCP, and can access only the portal server and predefined free websites.
After passing authentication, the user can access the network resources. The process of direct
authentication is simpler than that of re-DHCP authentication.
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Re-DHCP authentication
Before authentication, a user gets a private IP address through DHCP and can access only the
portal server and predefined free websites. After passing authentication, the user is allocated a
public IP address and can access the network resources. No public IP address is allocated to those
who fail authentication. This solves the IP address planning and allocation problem and can be
