R2511-HP MSR Router Series Security Configuration Guide(V5)

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The components of a portal system interact as follows:
1. When an unauthenticated user enters a website address in the browser's address bar to access the
Internet, an HTTP request is created and sent to the access device. The access device then redirects
the HTTP request to the portal server's Web authentication homepage. For extended portal
functions, authentication clients must run the portal client software.
2. On the authentication homepage/authentication dialog box, the user enters and submits the
authentication information, which the portal server then transfers to the access device.
3. Upon receipt of the authentication information, the access device communicates with the
authentication/accounting server for authentication and accounting.
4. After successful authentication, the access device checks whether there is a corresponding security
policy for the user. If not, it allows the user to access the Internet. Otherwise, the client
communicates with the access device and the security policy server for security check. If the client
passes security check, the security policy server authorizes the user to access the Internet
resources.
NOTE:
Portal authentication supports NAT traversal whether it is initiated by a Web client or an HP iNode client.
W
hen the portal authentication client is on a private network, but the portal server is on a public networ
k
and the access device is enabled with NAT, network address translations performed on the access device
do not affect portal authentication. However, in such a case, HP recommends using an interface's public
IP address as the source address of outgoing portal packets. You can also solve this problem by specifyin
g
the NAS-IP for outgoing RADIUS packets.
Portal system using the local portal server
In addition to using a separate device as the portal server, a portal system can also use the local portal
server function of the access device to authenticate Web users directly. In this case, the portal system
consists of only three components: authentication client, access device, and authentication/accounting
server, as shown in Figure 84.
Figure 84 Portal system using the local portal server
No security policy server is needed for local portal service, because the portal system using the local
portal server does not support extended portal functions.
The local portal server function of the access device implements only some simple portal server functions.
It only allows users to log on and log off through the Web interface. It cannot take the place of an
independent portal server.
Protocols used for interaction between the client and local portal server
HTTP 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.