From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Lameter Subject: Re: igmp: Staggered igmp report intervals for unsolicited igmp reports Date: Wed, 22 Sep 2010 16:33:14 -0500 (CDT) Message-ID: References: <4C9A6D87.2000103@rincon.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: David Stevens , "David S. Miller" , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" To: Bob Arendt Return-path: In-Reply-To: <4C9A6D87.2000103-x0S3BwdUo6DQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org On Wed, 22 Sep 2010, Bob Arendt wrote: > multicast traffic is received. While IGMPv2 defines an "Unsolicited Report > Interval" default of 10 seconds, it appears that this is a significant enough > issue that the later IGMPv3 document calls out a default of 1 second, and > goes on to define a "Robustness Variable" and talks about the same case that > Christoph is trying to mitigate. Actually that suggests a different way to reach the same goal: Subject: igmp: Make unsolicited report interval conform to RFC3376 RFC3376 specifies a shorter time interval for sending igmp joins. This can address issues where joins are slow because the initial join is frequently lost. Also increment the frequency so that we get a 10 reports send over a few seconds. Signed-off-by: Christoph Lameter --- net/ipv4/igmp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: linux-2.6/net/ipv4/igmp.c =================================================================== --- linux-2.6.orig/net/ipv4/igmp.c 2010-09-22 16:28:17.000000000 -0500 +++ linux-2.6/net/ipv4/igmp.c 2010-09-22 16:28:54.000000000 -0500 @@ -114,9 +114,9 @@ #define IGMP_V1_Router_Present_Timeout (400*HZ) #define IGMP_V2_Router_Present_Timeout (400*HZ) -#define IGMP_Unsolicited_Report_Interval (10*HZ) +#define IGMP_Unsolicited_Report_Interval (HZ) #define IGMP_Query_Response_Interval (10*HZ) -#define IGMP_Unsolicited_Report_Count 2 +#define IGMP_Unsolicited_Report_Count 10 #define IGMP_Initial_Report_Delay (1) -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html