Re: [ns] drop packets by ARP

[Stefan Rank <rank@informatik.tu-muenchen.de>]

boo sunn wrote:
> 
> hi:
> 
> Thanks for information.
> 
> Could you show me the code in ns-2 which does the
> "drop"?
> 

From file arp.cc

int
ARPTable::arpresolve(nsaddr_t dst, Packet *p, LL *ll)
{
        ARPEntry *llinfo ;
	
	assert(initialized());
	llinfo = arplookup(dst);

...

	llinfo->count_++;
	if(llinfo->hold_)
		drop(llinfo->hold_, DROP_IFQ_ARP_FULL);
	llinfo->hold_ = p;

	/*
	 *  We don't have a MAC address for this node.  Send an ARP Request.
	 *
	 *  XXX: Do I need to worry about the case where I keep ARPing
	 *	 for the SAME destination.
	 */
	int src = node_->address(); // this host's IP addr
	arprequest(src, dst, ll);
	return EADDRNOTAVAIL;
}


Rankster

> --- Stefan Rank <rank@informatik.tu-muenchen.de>
> wrote:
> > Hi,
> >
> > when a packet waits for its IP address to be
> > resolved into its
> > Hardwareaddress, the packet is buffered. When
> > another packet arrives
> > with the same IP address to be resolved, the
> > previous packet is dropped.
> >
> > Rankster
> >
> > boo sunn wrote:
> > >
> > > hi:
> > >
> > > I am using ns-2.18a, and after running a script, I
> > > analyze the trace file, and find that there are
> > some
> > > packets which are dropped due to "ARP" (from new
> > > trace).
> > >
> > > I use PT_TCP, so can someone tell me why these
> > packets
> > > are dropped?
> > >
> > > Thanks,
> > >
> > > bo sun
> > >
> > > __________________________________________________
> > > Do You Yahoo!?
> > > NEW from Yahoo! GeoCities - quick and easy web
> > site hosting, just $8.95/month.
> > > http://geocities.yahoo.com/ps/info1
> >
> 
> __________________________________________________
> Do You Yahoo!?
> NEW from Yahoo! GeoCities - quick and easy web site hosting, just $8.95/month.
> http://geocities.yahoo.com/ps/info1