multicast and multiple nics

[Giulio Ferro]

Thanks for the reply.

iprebeg at freebsd.org wrote:
>> I want to run ushare (/usr/ports/ushare). This program sends
>> multicast packets to multicast address 239.255.255.250
>>
>> The packets should go to the lan, so I add the route:
>> route add 224/4 -iface re0
>>
>> In order to do the test I switch off the firewall (/etc/rc.d/pf stop)
>>
>> I start the service, but no packets can be seen leaving the interface re0
>> with tcpdump.
>>     
>
> Can you try to sniff with other machine in that lan?
>   

Yes. Other machines can multicast without problem but nothing
multicast shows originating from the freebsd box.
>   
>> Even If I ping a multicast address directly I can see no packets at all:
>>
>> ping -I 192.168.2.1 239.255.255.250
>>     
I forgot mentioning that I can run this command from my linux box
and tcpdump from the same machine show the packets going to and fro.

>
> Please, try to use mcastread like this
>
> mcastread -v4 -s 192.168.2.1 re0 239.255.255.250 1337
>   
mcastread -v4 -s 192.168.2.1 re0 239.255.255.250 1337
mcastread: trying 239.255.255.250
mcastread: using (S,G)=(192.168.2.1,239.255.255.250)

And stays there..

> or mcastsend like this
>
> mcastsend -i re0 239.255.255.250 1337
>   
This results in an error:
mcastsend: setsockopt(IP_MULTICAST_IF): Can't assign requested address


Is there something else I can try?

Thanks again...