From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: linux kernel's IPV6_MULTICAST_HOPS default is 64; should be 1? Date: Mon, 03 May 2010 23:22:49 -0700 (PDT) Message-ID: <20100503.232249.200767273.davem@davemloft.net> References: <4BDF8387.4000303@hp.com> <20100503.230553.200626786.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: brian.haley@hp.com, netdev@vger.kernel.org To: enh@google.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:53693 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755459Ab0EDGWm (ORCPT ); Tue, 4 May 2010 02:22:42 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: enh Date: Mon, 3 May 2010 23:19:22 -0700 > for the *unicast* hops, a part of the RFC i didn't quote says: > > If the [IPV6_UNICAST_HOPS] option is not set, the > system selects a default value. > > but for the *multicast* hops, which is what i'm talking about, this > part of the quoted text seems pretty definitive: > > If IPV6_MULTICAST_HOPS is not set, the default is 1 > (same as IPv4 today) > > this is what my test shows isn't true of linux; linux reuses its > unicast default instead. Ok, I see, so yeah this needs to be fixed to use "1" instead of "-1" in the np->xxx ipv6 socket initialization.