From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <rick.jones2@hp.com>
Received: from g5t0006.atlanta.hp.com (g5t0006.atlanta.hp.com [15.192.0.43])
	(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
	(Client CN "smtp1.hp.com",
	Issuer "VeriSign Class 3 Secure Server CA - G2" (verified OK))
	by huchra.bufferbloat.net (Postfix) with ESMTPS id 7A019200153;
	Mon, 18 Jul 2011 10:00:47 -0700 (PDT)
Received: from g5t0029.atlanta.hp.com (g5t0029.atlanta.hp.com [16.228.8.141])
	by g5t0006.atlanta.hp.com (Postfix) with ESMTP id 0A5F6C01C;
	Mon, 18 Jul 2011 17:40:08 +0000 (UTC)
Received: from [16.89.244.213] (tardy.cup.hp.com [16.89.244.213])
	by g5t0029.atlanta.hp.com (Postfix) with ESMTP id F1F92200E7;
	Mon, 18 Jul 2011 17:40:07 +0000 (UTC)
Message-ID: <4E246FF7.7060405@hp.com>
Date: Mon, 18 Jul 2011 10:40:07 -0700
From: Rick Jones <rick.jones2@hp.com>
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US;
	rv:1.9.2.17) Gecko/20110424 Lightning/1.0b2 Thunderbird/3.1.10
MIME-Version: 1.0
To: Dave Hart <davehart_gmail_exchange_tee@davehart.net>
Subject: Re: smoketest #6 of cerowrt is go for testing
References: <CAA93jw6CaJ7LAF58HHXQt=tQd1DYXRrNUCrM-gd5JhTKJs0K8g@mail.gmail.com>	<CAMbSiYDp3A7LVp1yNaBZNTTe+OuzyMiGrGzBqNrd13dpgSUd+g@mail.gmail.com>	<4E2226B3.3070907@hp.com>
	<CAMbSiYBFNteUdRhBH2CgPL-SOEA2_DPgymK9VPHM_gAPYH=TVA@mail.gmail.com>
In-Reply-To: <CAMbSiYBFNteUdRhBH2CgPL-SOEA2_DPgymK9VPHM_gAPYH=TVA@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Cc: bismark-bootcamp@projectbismark.net,
	bloat-devel <bloat-devel@lists.bufferbloat.net>,
	bismark-devel@lists.bufferbloat.net
X-BeenThere: bloat-devel@lists.bufferbloat.net
X-Mailman-Version: 2.1.13
Precedence: list
List-Id: "Developers working on AQM, device drivers,
	and networking stacks" <bloat-devel.lists.bufferbloat.net>
List-Unsubscribe: <https://lists.bufferbloat.net/options/bloat-devel>,
	<mailto:bloat-devel-request@lists.bufferbloat.net?subject=unsubscribe>
List-Archive: <https://lists.bufferbloat.net/pipermail/bloat-devel>
List-Post: <mailto:bloat-devel@lists.bufferbloat.net>
List-Help: <mailto:bloat-devel-request@lists.bufferbloat.net?subject=help>
List-Subscribe: <https://lists.bufferbloat.net/listinfo/bloat-devel>,
	<mailto:bloat-devel-request@lists.bufferbloat.net?subject=subscribe>
X-List-Received-Date: Mon, 18 Jul 2011 17:00:47 -0000

On 07/16/2011 09:35 PM, Dave Hart wrote:
> On Sun, Jul 17, 2011 at 00:02 UTC, Rick Jones<rick.jones2@hp.com>  wrote:
>> If you configure ntpd with bare IP addresses rather than names, will the
>> getaddrinfo() return without attempting any DNS in the first place?
>
> Yes, basically.  ntpd might not even call getaddrinfo() in that case
> (it may use inet_pton() or similar to convert the IP address to binary
> representation).  At any rate, using only numeric IPv4 or IPv6
> addresses will avoid any DNS lookups.

If it does still call getaddrinfo(), like netperf does, and if it does 
happen to set AI_ADDRCONFIG, like netperf does, then the getaddrinfo() 
call for a bare IPv6 address will fail if there are only link-scope IPv6 
addresses assigned and the getaddrinfo() is the same as Ubuntu's.  This 
seems to be a change in the linux space since 2008, although I cannot 
say that conclusively because in 2008, netperf wasn't setting 
AI_ADDRCONFIG. But I have vague recollections of the calls working under 
linux since AI_ADDRCONFIG was set in netperf.

rick jones