HP MSR SERIES Configuration Manual page 350

If you remove an authentication or accounting server in use, the communication of the device
with the server will soon time out, and the device will look for a server in the active state by
checking any primary server first and then the secondary servers in the order they are
configured.
When the primary server and secondary servers are all in the blocked state, the device
communicates with the primary server. If the primary server is available, its statues changes to
active. Otherwise, its status remains to be blocked.
If one server is in the active state but all the others are in the blocked state, the device only tries
to communicate with the server in the active state, even if the server is unavailable.
After receiving an authentication/accounting response from a server, the device changes the
status of the server identified by the source IP address of the response to active if the current
status of the server is blocked.
• Set the real-time accounting interval based on the number of users.
Table 149 Recommended real-time accounting intervals
Number of users
1 to 99
100 to 499
500 to 999
>=1000
Real-time accounting interval (in minutes)
3
6
12
>=15
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