[Xorp-users] Very simple multicast setup, yet can't find any text on how to do it!

[Erik Slagter]

Update ;-)

Erik Slagter wrote:

> - As far as I know, it should be ok for a multicast group to be 
> forwarded regardless of the source address. If I set mc.mf6cc_origin to 
> all (binary) zeroes (bzero) and then call MRT6_ADD_MFC, it simply 
> doesn't work, it only works if I request the address from the  incoming 
> interface from the routing table, and fill the entry with that address 
> and the corresponding interface index, which I think is a dirty hack :-/ 
> Isn't there a way to specify a wildcard origin address and interface?

I looked this up in the kernel source and indeed there is no way to 
specify a wildcard address nor a wildcard interface :-(

> - When I start the program that feeds the multicast stream, before my 
> own program is started, the packets are routed to a (for me) random 
> interface. This is not always the same interface. It would be logical to 
> me if the packets are routed to the lo interface or are discarded 
> instead, when no "MRT6_INIT" program is running...

Also I experienced that the "active" non-multicast route tends to change 
at random points in time :-( That wouldn't be a problem if it weren't 
that packets are also forwarded to this route, regardless multicast routes.

I'll try to add an explicit route for every requested multicast group to 
my dummy0 interface. Maybe that helps.

> - Although I only request MLDv2 packets (143) I still get all sorts of 
> messages on the raw socket (icmp type 0, expected, probably "upcall" 
> packets) but also all sorts of other types?!

This seems to be a kernel bug (see other message).
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