This is the number of seconds the switch waits before resending an authentication request to the RADIUS or TACACS+ server if no response arrives. Tuning this balances authentication responsiveness against network latency: too low a value can flood a slow server with duplicate requests, too high delays failover to a backup server. An admin might raise this from a default of 3 seconds to 10 seconds if the AAA server sits across a high-latency WAN link.