(usagi-users 02970) Re: ipv6 multicast forwarding

[Pavlin Radoslavov <pavlin@xxxxxxxx>]

> Hi,
> 
> You should create ipv6/ip6mr.c like ipv4/ipmr.c
> 
> For more information about this development, you should have a look to 
> the multicast forwarding of BSD because ipv4/ipmr.c is based on IPv4 
> multicast forwarding from BSD. It means that ipv6/ip6mr.c could be a 
> port of BSD multicast forwarding too (with some differences ;-) ).

FWIW, almost an year ago the FreeBSD IPv4 multicast routing code was
updated and now it has some additional features that are not in
Linux IPv4 code or the BSD IPv6 code.

For example, some of the changes add the so-called advanced
multicast API which provides for incremental (backward-compatible)
addition of new features. Currently, those new features are:

 * In-kernel PIM Register encapsulation.
 * In-kernel multicast bandwidth monitoring and upcalls.
 * Support for explicit disabling of the WRONGVIF upcalls when
   they don't serve any purpose, but create lots of processing
   overhead.

The multicast(4) and pim(4) manual pages from FreeBSD-4.10 or 5.2
(or later) have all technical details (available online from
http://www.FreeBSD.org/cgi/man.cgi).

Obviously, the new features are not mandatory, but if someone is
considering implementing IPv6 multicast forwarding for Linux,
then it may be worth looking at them.

> The book "Architecture Linux Réseau" describes the multicast forwarding 
> process of the Linux Kernel 2.4.

BTW, is there an English version? ;)

> 
> Regards,
>   Vincent
> 
> Lahmadi Abdelkader wrote:
> 
> >hello;
> >does the latest usagi implementation have the ipv6 multicast forwarding 
> >support ? if no, any ideas please to do ipv6 multicast forwarding in linux, 
> >and any ipv6 implementation for PIM-SM ?

If the Linux kernel supports IPv6 multicast forwarding, and if it
uses at least the base IPv6 multicast routing API as defined by the
KAME implementation for BSD, then the XORP PIM-SM implementation
(http://www.xorp.org/) should be able to work on IPv6 Linux. Hence,
if someone has such IPv6 multicast forwarding patches and would like
to test them, please let me know and I will be glad to assist with
the testing.

Regards,
Pavlin