multicast routing

multicast routing

Post by Thorsten H. Niebuh » Wed, 31 Jan 2001 01:44:38

HI !

First: I am not that familiar with Linux, but i am able to compile a kernel.

Heres the problem

We are a training-center with 10 classrooms. the classrooms are prepared
with images and Norton Multicast Server /clients.
Before, we havent any trouble with that configuration. Now, i have to
seperate the net: each classroom one ip-subnet.
Because of that a tried to set up a linux router with dhcp-relay enabled. No
problem so far. Then, I tried to recompile the kernel for multicast and for
preperation of using mrouted, the multicast routing solution for Linux. I
used mrouted 3.9beta3. The Kernel is 2.2.14.

When i start a multicast-session, the client receives a proper IP-Adress
with dhcp, all parameters are correct. But the client cant connect with the
server.BTW, the Server is just 2 Hops away.
Starting mrouted -d, the mrouted finds his vifs0 and vifs1, sending
neighbor-request. When the multicast-client is up, the mrouted recognized it
as vif-multicast-member. shortly after that the kernel states an "warning:
setsockopt MRZ_ADD_MFC invalid argument error". what does that mean ?
is there anybody who managed to set up multicast routing with Norton Ghost ?
I tried the w2k, Nt and the netware Multicast-server, none of them worked.
any hints ?



1. adding multicast route to the kernel

Hi all,

I have a question which probably has a very simple answer.  I'm trying
to insert multicast routes into the kernel using setsockopt with
MRT_ADD_MFC on an IGMP socket... just like most multicast routing

What I want to do is to be able to say "all multicast packets going to
<mcast addr> from any source coming in from <incoming interface>
should go out on <outgoing interface>".  Now, I've looked at smcroute
code and pimd code.  What should mfcctl.mfcc_origin be set to when I
do the setsockopt() call?  Should it be set to ?  That doesn't
seem to work.  What value signifies "all IP addresses"??

I looked at ipmr_input() in ipmr.c in the kernel sources and found
that it does a "straight" cache lookup.  I mean, it just takes the
source IP address and the destination multicast address from the IP
datagram and does a cache lookup.  It doesn't try to do a "wildcard"

However, I know that routing daemons like PIMD have to add routes of
the form
(*, G).  And I did find that they set mfcctl.mfcc_origin to
But I'm not sure how it works for PIMD.

Any help is greatly appreciated.


2. sar under NCR UNIX

3. Help Multicast routing under Linux

4. 14 hours to compile kernel??????486sx 25 /4

5. multicast routing

6. Bootable rootdisk; root in ram?

7. How to set multicast routes ?

8. Public apology

9. multicast routing woith linux.

10. multicast routing with mrouted

11. about multicast routing.

12. multicast route

13. Linux multicast routing