By default it will take 10 seconds for authentication to fail due to an unresponsive RADIUS server
before is Cisco Nexus series switch reverts to another RADIUS server or local authentication. What is
one efficient way to improve the reaction time to a RADIUS server failure?

A.
Decrease the global RADIUS timeout interval to 5 seconds.

B.
Configure the RADIUS retransmission count and timeout interval per server, versus globally.

C.
Configure per server a test idle timer, along with a username and password.

D.
Decrease the global RADIUS retransmission count to 1.

Explanation:

http://www.cisco.com/en/US/docs/switches/datacenter/sw/4_1/nxos/security/configuration/guide/sec_radius.html#wp1561847