Setting HWTACACS timers
About HWTACACS timers and server status
The device uses the following timers to control communication with an HWTACACS server:
Server response timeout timer (response-timeout)—Defines the HWTACACS server response timeout timer. The device starts this timer immediately after an HWTACACS authentication, authorization, or accounting request is sent. If the device does not receive a response from the server within the timer, it sets the server to blocked. Then, the device sends the request to another HWTACACS server.
Real-time accounting timer (realtime-accounting)—Defines the interval at which the device sends real-time accounting packets to the HWTACACS accounting server for online users.
Server quiet timer (quiet)—Defines the duration to keep an unreachable server in blocked state. If a server is not reachable, the device changes the server status to blocked, starts this timer for the server, and tries to communicate with another server in active state. After the server quiet timer expires, the device changes the status of the server back to active.
The server quiet timer setting affects the status of HWTACACS servers. If the scheme includes one primary HWTACACS server and multiple secondary HWTACACS servers, the device communicates with the HWTACACS servers based on the following rules:
When the primary server is in active state, the device communicates with the primary server. When the primary server is unreachable, the device researches a secondary server in active status in the order they are configured.
When one or more servers are in active state, the device tries to communicate with these servers only, even if they are unreachable.
When all servers are in blocked state, the device only tries to communicate with the primary server.
If the primary server is unreachable, the device changes the server status to blocked and starts a quiet timer for the server. When the quiet timer of the server expires, the status of the server changes back to active. The device does not check the server again during the authentication, authorization, or accounting process.
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, authorization, or accounting attempt a failure.
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 an HWTACACS server's status changes automatically, the device changes this server's status accordingly in all HWTACACS schemes in which this server is specified.
Restrictions and guidelines
A short real-time accounting interval helps improve accounting precision but requires many system resources. When there are 1000 or more users, set a real-time accounting interval longer than 15 minutes.
Procedure
Enter system view.
system-view
Enter HWTACACS scheme view.
hwtacacs scheme hwtacacs-scheme-name
Set the HWTACACS timers. Choose the following tasks as needed:
Set the HWTACACS server response timeout timer.
timer response-timeout seconds
By default, the HWTACACS server response timeout timer is 5 seconds.
Set the real-time accounting interval.
timer realtime-accounting minutes
By default, the real-time accounting interval is 12 minutes.
Set the server quiet timer.
timer quiet minutes
By default, the server quiet timer is 5 minutes.