Multicast issue

English Network/Internet
1

Hi

Using opensuse 11.2
I have a soft listening on a multicase @ : 230.0.40.1
My ip is : 10.167.250.200/24

If the sender is in my network (e.g 10.167.250.210) I receive the packets.

If the sender is not in my net (e.g 10.166.100.100) I don’t receive the packets

So I guess the packets are filtered somewhere…

Should I change something in my soft (and what ?), or is it related to a net config param (missing route or whatever …) ?

Thanks

Chris

2

Hi,
most likely your router/switch/access point or whatever it is blocks multicasts. Check the configuration of your network device to enable multicast but be sure to do so only for your local network as it can be very dangerous if You will allow it for the public interface.

Best regards,
Greg

3

blinde wrote:
> Using opensuse 11.2
> I have a soft listening on a multicase @ : 230.0.40.1
> My ip is : 10.167.250.200/24
>
> If the sender is in my network (e.g 10.167.250.210) I receive the
> packets.
>
> If the sender is not in my net (e.g 10.166.100.100) I don’t receive the
> packets
>
> So I guess the packets are filtered somewhere…

All those addresses are “private network” addresses and as such are not
allowed to be transmitted onto the internet. So internet routers always
filter them. If the two networks are local to your organization, then
the router between those two networks is most likely filtering them and
would need adjusting. But it’s probably an indication that whatever
you’re trying to do can be done in a different way.

4

Although private addresses are used for unicasts, you’re properly using a public address for your multicasts.

So, I agree with glistwan that your problem may be your router (not all routers support multicasts).
You may also have a problem with “discovery.” Because your hosts are on private networks, there may not be a way for your hosts to find and communicate with each other.

Tony