[Xorp-users] Static joins

[Pavlin Radoslavov]

> James Courtier-Dutton wrote:
> > I have an application than generates a tunN interface.
> > XORP has this tunN interface as one of its PIM-SM/IGMP interfaces.
> > Now, I need to find the easiest way to get XORP to output multicast
> > traffic over this interface.
> > One option is for my application to create and send IGMP messages
> > towards the tunN interface.
> > I was hoping that there might be a XRL interface directly into XORP
> > that would simulate the IGMPs being received on the tunN interface by
> > XORP so that I would not have to reimplement IGMP in my application.
> >   

Do you know in advance the multicast group whose traffic needs to be
replicated on tunN?

If yes, in your application you can just join that group on
interface tunN (I assume the application is running on the XORP
host).
E.g., you need to use setsockopt(..., IP_ADD_MEMBERSHIP, ...) if
your application is in C/C++.
Then the kernel will generate the IGMP Join message and XORP should
forward the multicast data for that group on the tunN interface.

If you don't know in advance the multicast groups and you want to
forward all multicast traffic on tunN, then the solution would be
different.

Please clarify whether you need to forward all multicast groups or a
small pre-defined set of known groups.

Pavlin