Messages in this thread | | | Date | Fri, 4 Jun 2004 17:54:23 +0200 | From | "Wesley W. Terpstra" <> | Subject | Broken? 2.6.6 + IP_ADD_SOURCE_MEMBERSHIP + SO_REUSEADDR |
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Hi!
I am using the new IGMPv3 support in the 2.6.* series for Single Source Multicast (SSM). However, the kernel appears to (incorrectly) drop packets in some situations.
What I do is this: open a UDP port, set it SO_REUSEADDR, bind it to port 6767, and then use IP_ADD_SOURCE_MEMBERSHIP to listen to multicast group 232.65.43.21 and with a command-line controlled sender.
If I launch the same program twice with different senders, the first program ceases to receive multicast packets. (Neither from its own sender, nor the second program's sender) The second program receives packets from its designated sender only (as expected).
I know from tcpdump that the switch is delivering messages from the first designated sender. The kernel is simply not giving them to the application.
Some more observations:
If both programs specify the same sender, then both programs receive the message (as expected).
This is not an issue with subscribing to multiple senders in general. A single program listening to two senders does receive messages from both.
This seems like a bug to me.
PS. I am not subscribed to this list, so please CC me.
-- Wesley W. Terpstra - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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