F3726, F3211, F3174, R5135, R3816-HP Firewalls and UTM Devices Access Control Configuration Guide-6PW100

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With online portal user detection enabled on an interface, the device periodically sends probe packets
(ARP requests) to the portal users on the interface to check whether the portal users are still online, to find
portal users who get offline without logging off.
• If the device receives a reply from a portal user before sending probe packets to the portal user for
the maximum number of times, it considers that the portal user is online and keeps sending probe
packets to the portal user.
• If the device receives no reply from a portal user after sending probe packets to the portal user for
the maximum number of times, it considers that the portal user is offline and stops sending probe
packets to the portal user and deletes the user.
To configure online Layer 3 portal user detection:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Configure online Layer 3
portal user detection.
access-user detect type arp
retransmit number interval interval
Not configured by default.
NOTE:
A
djust the maximum number of transmission attempts and the interval of sendin
g
probe packets
according to the actual network conditions.
212BConfiguring the portal server detection function
During portal authentication, if the communication between the access device and portal server is
broken, new portal users are not able to log on and the online portal users are not able to log off normally.
To address this problem, the access device needs to be able to detect the reachability changes of the
portal server quickly and take corresponding actions to deal with the changes. For example, once
detecting that the portal server is unreachable, the access device allows portal users to access network
resources without authentication. This function is referred to as portal authentication bypass. It allows for
flexible user access control.
With the portal server detection function, the device can detect the status of a specific portal server. The
specific configurations include:
1. Detection methods (you can choose either or both)
{ Probing HTTP connections—The access device periodically sends TCP connection requests to
the HTTP service port of the portal servers configured on its interfaces. If the TCP connection
with a portal server can be established, the access device considers that the probe succeeds
(the HTTP service of the portal server is open and the portal server is reachable). If the TCP
connection cannot be established, the access device considers that the probe fails and the
portal server is unreachable.
{ Probing portal heartbeat packets—A portal server that supports the portal heartbeat function
(only the IMC portal server supports this function) sends portal heartbeat packets to portal
access devices periodically. If an access device receives a portal heartbeat packet or an
authentication packet within a probe interval, the access device considers that the probe
succeeds and the portal server is reachable. Otherwise, it considers that the probe fails and
the portal server is unreachable.