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/