netdev - IGMP Unsolicited Report Interval too long for IGMPv3?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <51ED998D.7000300@youview.com>
Date:	Mon, 22 Jul 2013 21:43:57 +0100
From:	William Manley <william.manley@...view.com>
To:	<netdev@...r.kernel.org>
Subject: IGMP Unsolicited Report Interval too long for IGMPv3?

If an IGMP join packet is lost you will not receive data sent to the 
multicast group so if no data arrives from that multicast group in a 
period of time after the IGMP join a second IGMP join will be sent.  The 
delay between joins is the "IGMP Unsolicited Report Interval".

In the kernel this seems to be hard coded to be chosen randomly between 
0-10s.  In our use-case (IPTV) this is too long as it can cause channel 
change to be slow in the presence of packet loss.

I would guess that this 10s has come from IGMPv2 RFC2236, which was 
reduced to 1s in IGMPv3 RFC3376.

There was a thread about this on linux-rdma in 2010 in the context of IP 
over Infiniband but it seems no patches got applied as a result of the 
discussion:

http://www.mail-archive.com/linux-rdma@vger.kernel.org/msg05740.html

Would the right patch reducing the unsolicited report interval for 
IGMPv3 be acceptable now?

Thanks

Will

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html