SQL IP Pool maximum timeout.

[Peter Nixon]

On Mon 09 Jul 2007, Hugh Messenger wrote:
> On Behalf Of Dave said:
> > Yes accounting is working well from the NAS
>
> Are you sure the NAS is sending 'interim update' accounting packets, not
> just start/stop?
>
> Here's my understanding of how it works (I'm sure Peter will correct me if
> I'm wrong!):
>
> On an access request, sqlippool will first check to see if this looks like
> a 'lost stop' case (allocate-clear) by checking to see if there are any
> assigned IP's in the pool with the same 'pool-key' (NAS-Port in a dialup
> context) as the request.  If so, free up that IP.
>
> Then it looks for an IP to assign (allocate-find), by checking for a free
> or expired IP in the pool, allocates it (allocate-update) and sets the
> expiry_time to "now + lease-duration".
>
> On an accounting 'stop', it frees up the IP (stop-clear).
>
> On an accounting 'update', it extends the expiry_time by 'lease-duration'
> seconds (alive-update).
>
> There's a little more to it than that (like accounting on/off), but that's
> the basic life cycle of an IP assignment.
>
> So ... if your NAS isn't sending accounting updates, then it will start
> re-assigning IP's after the initial expiry_time (lease-duration).  If your
> NAS doesn't implement accounting updates, you may have to set session
> timeouts to less than your lease-duration.

I couldn't have summarised it any better :-)


-- 

Peter Nixon
http://peternixon.net/