H3C S5830V2 Security Configuration Manual page 49

Step
3. Specify a source IP
address for outgoing
HWTACACS packets.
Setting HWTACACS timers
The device uses the following timers to control the 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 after the timer expires, it sets the server to blocked and sends the request to another
HWTACACS server.
Real-time accounting timer (realtime-accounting)—Defines the interval at which the device sends
•
real-time accounting updates to the HWTACACS accounting server for online users. To implement
real-time accounting, the device must periodically send real-time accounting packets for online
users to the accounting server.
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's 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 status of HWTACACS servers controls the HWTACACS servers with which the device communicates
when the current servers are no longer available. You can specify one primary HWTACACS server and
multiple secondary HWTACACS servers, with the secondary servers functioning as the backup of the
primary servers. Typically, the device chooses servers based on the following rules:
When the primary server is in active state, the device communicates with the primary server.
•
If the primary server fails, the device changes the server's status to blocked, starts a quiet timer for
the server, and tries to communicate with a secondary server in active state (a secondary server
configured earlier has a higher priority).
If the secondary server is unreachable, the device changes the server's status to blocked, starts a
quiet timer for the server, and continues to check the next secondary server in active state. This
search process continues until the device finds an available secondary server or has checked all
secondary servers in active state.
If the quiet timer of a server expires, the status of the server changes back to active, but the device
does not check the server again during the authentication or accounting process.
If no server is found reachable during one search process, the device considers the authentication
or accounting attempt a failure.
If you remove an authentication or accounting server in use, the communication of the device with
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the server soon times out, and the device looks for a server in active state by first checking the
primary server and then secondary servers in the order they are configured.
When the primary server and secondary servers are all in blocked state, the device does not
•
communicate with any server.
• If one server is in active state and all the others are in blocked state, the device tries to communicate
with the server in active state only, even if the server is unavailable.
Command
nas-ip { ipv4-address | ipv6
ipv6-address }
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Remarks
By default, the device uses the IP address
specified by the hwtacacs nas-ip
command in system view as the source IP
address. If no IP address is specified, the
device uses the IP address of the
HWTACACS packet outbound interface as
the source IP address.