o  enable mac address failed
    The attempt to enable the MAC address failed on a broadcast
    circuit with a nonzero Phase IV address.
 o  no such data link
    Data link specified for this circuit does not exist.
 o  open port failed
    A port cannot be opened on the specified data link.
 o  open rip port failed
    The UDP port for RIP (port 520) could not be created.
 o  routing not enabled
    The Routing module is not in the on state.
 o  subnet address not unique
    One of the subnet addresses for this circuit is the same as the
    subnet address for another circuit.