[ELDK] TUN/TAP kernel driver in Linux 2.6.13 of ELDK-4.1

[linuxdemo]

 when I using the TUN/TAP driver (compiled into the kernel) with the 2.6.13 kernel of Eldk-4.1, then I add device file as lists:
    #mknod /dev/net/tun c 10 200
     #mknod /dev/tap0 c 3616
    I seems broken to me..
    
    when I bring up tun0/tap0 interface,I met two errors as lists:
    # ifconfig tun0 tun0: error fetching interface information: Device not found (As with any interface that's not recognized by ifconfig..) 
    # cat /dev/net/tun cat: File descriptor in bad state
    can you tell me why? Thanks!!

                                                 2008.8