ISDN Status & Network Device Interfaces

[Igor]

Hi All,
I've just configured my Fedora installation to connect to
my ISP thru ISDN Connection.

I dialup by activating the ippp0 interface by the Network Device
interface tool.
It dialup normally and connect successfully to my ISP but the ippp0
interface remains in "Inactive" state.

I can't disconnect thru the same tool: now I use ifconfig ippp0 down.

It's not a problem unless, by typing "ifconfig -a" by the Terminal 
(in XFree), It shows alway my ippp0 interface up as if it wasn't brought down.

Switching in textmode Console, the same command (ifconfig -a) doesn't 
show the ippp0 interface.

Does Terminal "cache" the command output ?

Why doesn't "Network Interface" tool recognize my ISDN interface up ?

Thanks,
Igor.