HP-UX AAA Server A.08.00.01 Administrator's Guide

information can be used to identify the external service accessed to process the
RADIUS request.
Some external service failures do not result in the HP-UX AAA Server recording
a message in the server logfile. For example, if the HP-UX AAA Server times out
on waiting on a busy database server, it does not record an error in the logfile. No
reply is sent to the RADIUS client.
Protocol Limitations
The HP-UX AAA Server communicates with the RADIUS client using the RADIUS
protocol. The RADIUS protocol has the following limitations:
• RADIUS packets are transmitted using the connectionless UDP transport protocol.
Therefore, a RADIUS request that does not reach the recipient needs to be
retransmitted by the sender. Usually, the sender retransmits the request if it times
out while waiting for the acknowledgement.
• The RADIUS protocol specification allows the HP-UX AAA Server to send
Access-Accept and Access-Reject messages only, in response to an Access-Request.
The HP-UX AAA Server cannot send status information about a request to the
RADIUS client.
Messages that do not contain correct information in accordance with the RADIUS
protocol specifications will be silently discarded by the HP-UX AAA Server without
any reply or status being sent to the client
Supplicants connecting to the HP-UX AAA Server over a WLAN can use EAP protocols.
The same EAP protocols must be configured at the supplicant, access point, and HP-UX
AAA Server EAP realm configuration.
RADIUS Client and Supplicant Considerations
The HP-UX AAA Server supports several RADIUS clients, supplicants, and OTP token
generators. For a list of RADIUS clients, supplicants, and OTP token generators that
have been certified for the HP-UX AAA Server, see the HP-UX AAA Server A.08.00.01
Release Notes (T1428-90067). Consider the following:
• If the RADIUS client does not receive a reply from the HP-UX AAA Server, it
behaves as if the HP-UX AAA Server is offline. It can retransmit the request after
the timeout to the same HP-UX AAA Server or a secondary HP-UX AAA Server,
based on the configuration.
• Not all RADIUS clients maintain an error log.
Probable Causes for Failure 459