Re: [lwip-users] Multicast Example?

[Jonathan Ross]

Thanks for the response!

I did this, and now I can subscribe, but my implementation is ignoring IGMP 
membership queries from the router and so gets dropped after a couple of 
minutes. Is there something I'm supposed to do to get this to work, or is my 
(Xilinx) implementation broken?

Also, I'm not sure how to get data being sent to the group I've joined. What 
function gets called when I receive a UDP packet sent to the group I'm 
subscribed to? I see it in wireshark as a packet sent to the group I'm 
listening to in UDP form to a specific port, but my udp_recv function, which is 
bound to IP_ADDR_ANY, and that port, is never called.

Thanks!
Jonathan

On Dec 18, 2009, at 12:40 PM, Joe Dupre wrote:

> I have this line:
> 
> netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP 
> | NETIF_FLAG_IGMP;
> 
> In low_level_init() [ethernetif.c]
> 
> You have to have the IGMP flag set somewhere.
> 
> - Joe
> 
> 
>>>> Also, xemac_add calls netif_add, and within which there is the
>> following
>>>> code:
>>>> 
>>>> netif->flags = 0;
>>>> 
>>>> // ...
>>>> 
>>>> #if LWIP_IGMP
>>>> /* start IGMP processing */
>>>> if (netif->flags & NETIF_FLAG_IGMP) {
>>>>   igmp_start( netif);
>>>> }
>>>> #endif /* LWIP_IGMP */