Interaction Between Portal System Components; Portal Authentication Modes - HP FlexFabric 5700 Series Security Configuration Manual

Interaction between portal system components

The components of a portal system interact as follows:
1. An unauthenticated user initiates authentication by accessing an Internet website through a Web
browser. When receiving the HTTP request, the access device redirects it to the Web
authentication page provided by the portal Web server. The user can also visit the authentication
website to log in. The user must log in through the HP iNode client for extended portal functions.
2. The user enters the authentication information on the authentication page/dialog box and submits
the information. The portal Web server forwards the information to the portal authentication server.
Then the portal authentication server processes the information and forwards it to the access
device.
3. The access device interacts with the AAA server to implement authentication, authorization,
accounting for the user.
4. If security policies are not imposed on the user, the access device allows the authenticated user to
access the Internet. If security policies are imposed on the user, the portal client, the access device,
and the security policy server interact to check the user host. If the user passes the security check,
the security policy server authorizes the user to access resources based on the check result. Portal
authentication through Web does not support security check for users. To implement security check,
the client must be the HP iNode client.
NOTE:
Portal authentication supports NAT traversal whether it is initiated by a Web client or an HP iNode client.
NAT traversal must be configured when the portal client is on a private network and the portal server is on
a public network.

Portal authentication modes

Portal authentication has three modes: direct authentication, re-DHCP authentication, and 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 can exist between the authentication client and the access device.
Direct authentication
A user manually configures a public IP address or obtains a public IP address through DHCP. Before
authentication, the user can access only the portal Web server and predefined authentication-free
websites. After passing authentication, the user can access other network resources. The process of direct
authentication is simpler than that of re-DHCP authentication.
Re-DHCP authentication
Before a user passes authentication, DHCP allocates an IP address (a private IP address) to the user. The
user can access only the portal Web server and predefined authentication-free websites. After the user
passes authentication, DHCP reallocates an IP address (a public IP address) to the user. The user then can
access other network resources. No public IP address is allocated to users who fail authentication.
Re-DHCP authentication saves public IP addresses. For example, an ISP can allocate public IP addresses
to broadband users only when they access networks beyond the residential community network.
Only the HP iNode client supports re-DHCP authentication. IPv6 portal authentication does not support
the re-DHCP authentication mode.
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