RADIUS/PPPoE Dead Connections

[Jeremy Tregunna]

I've got a FreeBSD NAS and a FreeBSD RADIUS server (both running 6.1)  
serving up access to a wireless network. In any event, everything  
seems to work peachy when a user logs in and disconnects manually.  
But if for instance, someone closes the lid on their laptop and their  
wireless card powers off due to standby mode, the connection to the  
NAS is broken and the disconnect request never makes it from the NAS  
to the RADIUS server to inform it that the client went offline.

Now then, I'm not so much worried about that stale entry staying on  
the RADIUS server until the user tries to log in again (I don't care  
much about time used, only bandwidth numbers); but ultimately it  
would be nice to have one of two solutions:

(1) A user tries to log in when he's already logged in, have it  
disconnect that user and then log in; or
(2) Have the NAS send a Disconnect-Request to the RADIUS server when-- 
as in the above example--someone closes the lid on their laptop.

An idle timeout isn't a workable solution for me, neither is a  
session timeout; I need both to have no fixed limit for all clients.

My ppp.conf file is basically defined as:

### ppp.conf begin

default:
   set log Chat Command Phase
   enable pap
   allow mode direct
   enable proxy
   disable ipv6cp
   set radius /etc/radius.conf
   set mru 1492
   set mtu 1492
   accept dns

### end ppp.conf

The relevant users portion is like:

DEFAULT Auth-Type := System
         Service-Type := Framed-User,
         Framed-Protocol := PPP,
         Framed-IP-Address := 192.168.8.50,
         Framed-IP-Netmask := 255.255.255.0,
         Framed-Routing := Broadcast-Listen,
         Framed-MTU := 1492

And the relevant portions of attrs is like:

DEFAULT
	Service-Type == Framed-User,
	Framed-Protocol == PPP,
	Framed-MTU == 1492,
	Framed-Filter-ID =* ANY,
	Reply-Message =* ANY,
	Session-Timeout == 0,
	Idle-Timeout == 0,
	Port-Limit <= 2

Any assistance would be greatly appreciated.

Regards,

Jeremy Tregunna