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

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2. The portal server and the access device exchange CHAP messages. This step is skipped for PAP
authentication.
3. The portal server assembles the username and password into an authentication request message
and sends it to the access device. Meanwhile, the portal server starts a timer to wait for an
authentication reply message.
4. The access device and the RADIUS server exchange RADIUS packets to authenticate the user.
5. The access device sends an authentication reply to the portal server.
6. The portal server sends an authentication success message to the authentication client to notify it of
logon success.
7. The portal server sends an authentication reply acknowledgment message to the access device.
With extended portal functions, the process includes additional steps:
8. The security policy server exchanges security check information with the authentication client to
check whether the authentication client meets the security requirements.
9. Based on the security check result, the security policy server authorizes the user to access certain
resources, and sends the authorization information to the access device. The access device then
controls access of the user based on the authorization information.
Re-DHCP authentication process (with CHAP/PAP authentication)
Figure 88 Re-DHCP authentication process
The re-DHCP authentication process is as follows:
Step 1 through step 6 are the same as those in the direct authentication/cross-subnet authentication
process.
7. After receiving the authentication success message, the authentication client obtains a new public
IP address through DHCP and notifies the portal server that it has obtained a public IP address.
Authentication/
accounting server
Authentication
client
Portal server
Access device
6) Authentication
succeeds
Security
policy server
12) Security check
13) Authorization
7) The user obtains
a new IP address
8) Discover user IP change
10) Notify login
success
9) Detect user IP change
11) IP change
acknowledgment
Timer
1) Initiate a connection
2) CHAP authentication
3) Authentication request
5) Authentication reply
4) RADIUS
authentication