Freeradius load balancing.

[Alan DeKok]

nick wrote:
> At the moment we have a freeradius 1.1.3 server on CentOS which is
> functioning fine, but due to circumstances, and the devices we are using
> as NASes, the ip pools are located on the NAS instead of being
> centralized on the RADIUS server as we'd like it.

  You should really upgrade to a more recent version.

> We'd now like to make things a bit more robust, including a clustered
> MySQL backend for AAA, and, if possible, load balanced freeradius
> servers on the front end.
> 
> We'd also like to use SQL ip pools. I am only unsure about one thing
> though. If we have a shared pool available via DB, what prevents the two
> load balanced radius instances from giving out the same ip address?

  For one, SQL IP pools are likely to *not* work in 1.1.3.  There were a
number of fixes put into 2.x that solved those problems.

> I've been doing a fair bit of googling, but without a whole lot of luck
> in this respect.

  MySQL is a DB.  If it exports a transactional API, then it doesn't
matter if two RADIUS servers are allocating IP's simultaneously.

  Alan DeKok.