[ns] How to dynamically stop a node from forwarding packets?

[Gustavo Da Costa <gmc50@student.canterbury.ac.nz>]

Hi,

I would like to stop packets from being forwarded from a specific node
when this node receives a packet of a specific type (say type a) and
restart forwarding packets when the node receives a packet of another
type (say b). Does anybody know which file I should look at modifying?

I tried blocking the queue associated with a node to do that. If the
node to be blocked is at a bottleneck link then the queue was blocked.
However, if the node is not at a bottleneck link, the node continues to
forward packets as there is no queuing in the node.

Any suggestions would be really appreciated.

Thanks a lot,

Gustavo.