Re: multicast on some links

[Yuri Pryadkin <yuri@who.isi.edu>]

Lloyd Wood <L.Wood@surrey.ac.uk> writes:

> On Mon, 28 Sep 1998, Thomas Engberg wrote:
> 
> > I wonder if it is possible to have multicast (Simulator set
> > NumberInterfaces 1) on just some links in the topology? Is it hard to
> > change the implementation so this will work?
> 
> There are multicast and unicast nodes; to have multicast on just some
> links, you'd presumably have the other links connecting unicast-only
> nodes. 
> 
> What happens if you
> 
> set ns [new Simulator]
> 
> set EnableMcast_ 0
> # create unicast nodes for unicast parts of network here
> 
> set EnableMcast_ 1
> # create multicast-capable nodes for multicast-aware parts of network here
> 
> ?
> 

You can try that, or you can configure all nodes as multicast, and
then just drop multicast packets at those which you want to be
"unicast only".  That shouldn't be hard to implement.  It might, as
Ahmed said, not work well with some multicast routing protocols, so
you'd need to write your own.