Authentication services
Using a third-party RADIUS server
11-8
RADIUS servers, if a secondary server is defined. A reply that is received after the 
retry interval expires is ignored.
Retry interval applies to access and accounting requests that are generated by the 
following:
 Manager or operator access to the management tool
 User authentication by way of HTML
 MAC-based authentication of devices
 Authentication of the controller
 Authentication of the controlled AP.
You can determine the maximum number of retries as follows:
 HTML-based logins: Calculate the number of retries by taking the setting for the 
HTML-based logins Authentication Timeout parameter and dividing it by the 
value of this parameter. Default settings result in 4 retries (40 / 10).
 MAC-based and controller authentication: Number of retries is infinite.
 802.1X authentication: Retries are controlled by the 802.1X client software.
 Authentication method: Select the default authentication method that the 
controller uses when exchanging authentication packets with the RADIUS server 
defined for this profile. For 802.1X users, the authentication method is always 
determined by the 802.1X client software and is not controlled by this setting. If 
traffic between the controller and the RADIUS server is not protected by a VPN, it is 
recommended that you use either EAP-MD5 or MSCHAP V2 (if supported by your 
RADIUS Server). PAP and MSCHAP V1 are less secure protocols.
 NAS ID: Specify the identifier for the network access server that you want to use for 
the controller. By default the serial number of the controller is used. The controller 
includes the NAS-ID attribute in all packets that it sends to the RADIUS server.
 Always try primary server first: Enable this option if you want to force the 
controller to contact the primary server first. 
Otherwise, the controller sends the first RADIUS access request to the last known 
RADIUS server that replied to any previous RADIUS access request. If the request 
times out, the next request is sent to the other RADIUS server if defined. 
For example, assume that the primary RADIUS server was not reachable and that the 
secondary server responded to the last RADIUS access request. When a new 
authentication request is received, the controller sends the first RADIUS access 
request to the secondary RADIUS server.
If the secondary RADIUS server does not reply, the controller retransmits the 
RADIUS access request to the primary RADIUS server. When two servers are 
configured, the controller always alternates between the two.