Re: [ns] ARP question

[Aman Singla <aman@atheros.com>]

A real world stack normally buffers only a single packet in the
ARP module - a one deep queue.

:a

> Hello.
> Does anyone know how a real arp works?
> 
> The current arp works as follows: if a packet arrives and needs
> the MAC address of a certain destination, an ARP request is sent
> and the packet is stored in a buffer. Now if another packet
> arrives that needs the same MAC address, the previous packet is
> dropped, and the last packet arrived is stored in the buffer.
> 
> I was wondering if in real-life ARPs there is a queue of some
> kind which can store more than one packet while the ARP is
> fetching a certain MAC address?
> 
> I'm working on an Ad-Hoc routing protocol and I hope it will be
> a contribution to ns some day, and so I would like to know
> whether it would be better:
> -to have my protocol work with the current ARP
> -or to contribute the current version of my protocol + the
> correction I made to ARP (I added a queue: ARP doesn't drop any
> packets anymore.)
> 
> here is the comment that can be found in ARP.cc (in today's
> snapshot)
> /*
>          *  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.
> */
> 
> Thanks,
> --
> Robin