FreeBSD as multicast router

[Mike Karels]

> > > > Hi All
> > > > 
> > > > I have (noob) questions about multicast routing under FreeBSD.
> > > > 
> > > > I have FreeBSD box with two (or more) multicast enabled interfaces (e.x. 
> > > > vlan750 and vlan299).  vlan750 connected to multicast source.
> > > > 
> > > > Then pimd installed and only this two interfaces enabled in pimd config. 
> > > > Multicast routes successfully installed by pimd and listed by `netstat 
> > > > -g -f inet`
> > > > 
> > > > Then client on vlan299 send IGMP-Join (this Join received by FreeBSD on 
> > > > vlan299)
> > > > 
> > > > The question is:  who will forward muilticast from one interface 
> > > > (vlan750) to another (vlan299)?  Is it kernel specific job or I need 
> > > > additional software?
> > 
> > > Please read the manpage multicast(4) "man 4 multicast",
> > > you should need to build a custom kernel with the "options MROUTING"
> > > to enable the multicast forwarding in the kernel.
> > 
> > If "netstat -g" shows routes, the kernel must have been built with "options
> > MROUTING".

> Indeed.

> > 
> > The kernel does the forwarding, according to those routing tables installed
> > by pimd or another multicast routing program.  Is it not working?  It sounds
> > like you are very close.

> Could it be sysctl net.inet.ip.forwarding?  Does that still apply to mroutes?

No, they are separate.  The test is just whether MROUTING is enabled, and
whether a multicast router like pimd is active.

One other thing to check would be "netstat -gs" (multicast stats).

> > 
> > > > Victor Gamov
> > 
> > > -- 
> > > Rod Grimes                                                 rgrimes at freebsd.org
> > 
> > Mike
> -- 
> Rod Grimes                                                 rgrimes at freebsd.org

Mike