HP FlexNetwork 10500 Series Security Configuration Manual page 42

Setting the status of RADIUS servers
To control the RADIUS servers with which the device communicates when the current servers are no
longer available, set the status of RADIUS servers to blocked or active. You can specify one primary
RADIUS server and multiple secondary RADIUS servers. The secondary servers act as the backup
of the primary server. When the RADIUS server load sharing feature is disabled, the device chooses
servers based on the following rules:
•
When the primary server is in active state, the device communicates with the primary server.
•
If the primary server fails, the device performs the following operations:
Changes the server status to blocked.
Starts a quiet timer for the server.
Tries to communicate with a secondary server in active state that has the highest priority.
•
If the secondary server is unreachable, the device performs the following operations:
Changes the server status to blocked.
Starts a quiet timer for the server.
Tries to communicate with the next secondary server in active state that has the highest
priority.
•
The search process continues until the device finds an available secondary server or has
checked all secondary servers in active state. If no server is available, the device considers the
authentication or accounting attempt a failure.
•
When the quiet timer of a server expires or you manually set the server to the active state, the
status of the server changes back to active. The device does not check the server again during
the authentication or accounting process.
•
When you remove a server in use, communication with the server times out. The device looks
for a server in active state by first checking the primary server, and then checking secondary
servers in the order they are configured.
•
When all servers are in blocked state, the device only tries to communicate with the primary
server.
•
When one or more servers are in active state, the device tries to communicate with these active
servers only, even if the servers are unavailable.
•
When a RADIUS server's status changes automatically, the device changes this server's status
accordingly in all RADIUS schemes in which this server is specified.
•
When a RADIUS server is manually set to blocked, server detection is disabled for the server,
regardless of whether a test profile has been specified for the server. When the RADIUS server
is set to active state, server detection is enabled for the server on which an existing test profile
is specified.
By default, the device sets the status of all RADIUS servers to active. However, in some situations,
you must change the status of a server. For example, if a server fails, you can change the status of
the server to blocked to avoid communication attempts to the server.
When RADIUS server load sharing is enabled, the device distributes the workload over all servers
without considering the primary and secondary server roles. The device checks the weight value and
number of currently served users for each active server, and then determines the most appropriate
server in performance to receive an AAA request.
In RADIUS server load sharing, once the device sends a start-accounting request to a server for a
user, it forwards all subsequent accounting requests of the user to the same server. If the accounting
server is unreachable, the device returns an accounting failure message rather than searching for
another active accounting server.
To set the status of RADIUS servers:
28