[Click] Building a packet reflector in click

[david johnson]

Hi 

I presented a course on click today - used a lot of material from
University of Antwerp - thanks Bart and Michael. I thought up some
tutorials for them to practice their concepts and I thought building a
packet reflector would be easy - until I tried to solve it

I tried something like this:

define($DEV ath0)

FromDevice($DEV)
  -> c :: Classifier(12/0800, 12/0806 20/0002)
  -> CheckIPHeader(14)
  -> IPMirror
  -> StripToNetworkHeader
  -> Print ("Before ARP",200)
  -> arpq :: ARPQuerier($DEV)
  -> Print ("After ARP",200)
  -> IPPrint
  -> q :: Queue
  -> ToDevice($DEV)


arpq[1] -> q;
c[1] -> [1] arpq;

But it doesn't work - the IP address swapping is working - but it never
gets to the Print("After ARP",200) statement.

Is this a hard problem or is their a simple solution that I'm missing

I'm trying to think out a set of click exercises that get progressively
harder for the students to  do. Firstly without writing their own
elements and then with including writing their own elements - any ideas
will be most welcome. This would probably be a nice addition to the
documentation - exercises like these and their solutions. 

Regards
David