Required Clarification

[Benedikt Panzer]

Hello,

I'm not really experienced with FR, but maybe this is enough to help you.

 > 3) How does it maintains database does it uses SQL, if so ? whether 
it provides any
 > alternative to maintain database of username and password ? for 
example like by using files….. etc.

FR is able to store users and their attributes in a couple of backends 
including sql database and a users text file. See the modules section of 
radiusd.conf for more information.

> 1) What is the maximum length of username and password allowed in 
> freeRADIUS ?
>
That probably depends on the backend you're using, or look in 
http://www.freeradius.org/rfc/rfc2865.html if there's a limit.

> 2) What is the maximum number of users allowed to authenticate? I 
> mean, how many users does it maintains in its database?
>
I guess that's a question of performance first. Propably all backends 
can store _enough_ users and FR can also handle them.

> 4) Is there any necessity or possibility to use secondary RADIUS server ?
>
Technically it's not necessary. But if you use it for something 
important it's obvious better to have one... ;-) It's possible of course 
to set up 2 RADIUS servers.