I'm a non native speaker, so please accept my apologies if I'm not totally clear with my language. It's an issue with a net equipment that implements VPN connections and an the authentication server (implemented with Freeradius).

We work with several software providers who connect with our Intranet through the VPN, in order to make their web applications maintenance tasks. The clients are connected without problems for a long period of time during the night. But eventually the Freeradius (or vpn appliance, we don't know for certain) suddently disconnect the clients from the VPN during the next day in the morning (when our partners are working). Actually several times (maybe 6 times).

They should login again (via automated pppd script and a watchdog). This watchdog also tries to keep open the VPN and if it's not open, it tries to reconnect the VPN again (like a heartbeat).

The error we've seen in the log (we've used radmin and raddebug tools) is:

But in the Radius Accounting RFC (http://freeradius.org/rfc/rfc2866.html) this value is not permitted (possible values are 1-18).

This is a piece of log, where you can see when a client disconnect from the vpn:

Mon Jan 16 09:19:54 2012

Acct-Session-Id = "<sess_id_num>"

Tunnel-Server-Endpoint:0 = "<IP_1>"

Tunnel-Client-Endpoint:0 = "<IP_2>"

Tunnel-Assignment-Id:0 = "PPTP"

Framed-Protocol = PPP

Framed-IP-Address = <IP_3>

User-Name = "<usr_name>"

Acct-Authentic = RADIUS

Acct-Session-Time = 125159

Acct-Input-Octets = 1312452

Acct-Output-Octets = 2391455

Acct-Input-Packets = 19372

Acct-Output-Packets = 25170

Acct-Status-Type = Stop

NAS-Port-Type = Virtual

NAS-Port = 323

Service-Type = Framed-User

NAS-IP-Address = <IP_4>

Acct-Delay-Time = 0

Huntgroup-Name = "PPTP"

Acct-Unique-Session-Id = "<acct_sess_id>"

Stripped-User-Name = "<usr_name>"

Realm = "NULL"

Timestamp = 1326701994

Request-Authenticator = Verified

<sess_id_num>, <acct_sess_id>, <IP_x> and <usr_name> aren't real values (they're masked for privacy) although I think the error isn't related to them.

Thank you very much in advance!!