[ndnSIM] Doubts regarding NACK: Could not detect NACK

[madhurima buragohain]

I want to send a NACK to the downstream when the PIT approaches it limit

void
Forwarder::onIncomingInterest(Face& inFace, const Interest& interest)
{
.............
if (m_pit.size()< 20)
{
lp::Nack nack(interest);
nack.setReason(lp::NackReason::X );
inFace.sendNack(nack);
}
............
}

But when I want to print a statement in the below function:
void
Forwarder::onIncomingNack(Face& inFace, const lp::Nack& nack)
{

    std::cout <<"\nNACK is received\n";
..................

}

The statement is not printed.
I could not figure out the reason. Could anyone please help me?

PS: I have modified the nack-header.cpp file for introducing new NACK X.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.lists.cs.ucla.edu/pipermail/ndnsim/attachments/20180918/27673fe8/attachment.html>