[ns] ns problem

[ali bala]

hi
i wrote a simple example and run at ns but i see this:

--- Classfier::no-slot{} default handler (tcl/lib/ns-lib.tcl) ---
        _o18: no target for slot -1
        _o18 type: Classifier/Hash/Dest
content dump:
classifier _o18
        0 offset
        0 shift
        2147483647 mask
        1 slots
                slot 2: _o116 (Classifier/Port)
        -1 default
---------- Finished standard no-slot{} default handler ----------

i havent understanding about that
i wanted to know about that
thanks