FreeBSD as multicast router

[Eugene Grosbein]

07.11.2019 21:17, Victor Gamov wrote:

> I still have misunderstood here.  Pimd installs multicast routes and this routes displayed by `netstat -g`.
> So, the system knows interface where multicast received.
> When Join received  via interface 2 (vlan299) who must resend multicast from input interface 3 (vlan750)
> to output interface 2 (vlan299)?  I guess it kernel-specific task  and kernel must resend multicast
> without any other helpers.  Is it wrong?

I'm not familiar with multicast routing in FreeBSD.
Multicast routing has its rules in general, though.

For example, Cisco routers never process incoming multicast UDP flows if unicast route
to source IP address of UDP packets points to interface that differs from real incoming interface.
This is "reverse path filtering" embedded in multicast routing unconditionally.