From owner-freebsd-net@FreeBSD.ORG Tue Jul 22 18:25:43 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 127A1C59; Tue, 22 Jul 2014 18:25:43 +0000 (UTC) Received: from mail-wi0-x231.google.com (mail-wi0-x231.google.com [IPv6:2a00:1450:400c:c05::231]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 57C3224ED; Tue, 22 Jul 2014 18:25:42 +0000 (UTC) Received: by mail-wi0-f177.google.com with SMTP id ho1so908268wib.16 for ; Tue, 22 Jul 2014 11:25:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=mMzqum3sQh1daQ/RX+P+8IBCpDR1JwHfrCLZm6fKLJI=; b=RcPqf19eaXvbDYWiX5B8EAUUxlbP9ybJKOQkH533+QKQx5PybqZFannOVpvMXdUmkN 2sT14CDfqGQE8jYGFNmnLBfHrdM0K5P7vFGA7UnvAN3nfYr/Pe3eSF67Xr+O26mLf62c fdqZh0J9kIfBDoaDm/WM7RIE1Fsa5jQ1itQv8zw3P0RZL0mRaPgUp+7jWz3en5J09Ut8 pZG4kL74+6bKCNHttimict0fFm5ENd0K+xZq7C15PrjzhkFA/kn3LChlTUBkVJvDw+au IB7vC3Vbeko/rUIeYDM6qMfJ6NziF7eHfHpMWYirMf91Z4/YM+kduat3Blp34dpjyuu6 rsdA== MIME-Version: 1.0 X-Received: by 10.194.63.228 with SMTP id j4mr37150106wjs.7.1406053537979; Tue, 22 Jul 2014 11:25:37 -0700 (PDT) Sender: jinmei.tatuya@gmail.com Received: by 10.194.108.166 with HTTP; Tue, 22 Jul 2014 11:25:37 -0700 (PDT) In-Reply-To: <20140722170150.GA971@mx.elandsys.com> References: <20140720090410.GA7990@mx.elandsys.com> <20140722170150.GA971@mx.elandsys.com> Date: Tue, 22 Jul 2014 11:25:37 -0700 X-Google-Sender-Auth: hsPksJYTLMziCmxT9KtuGWXFrBI Message-ID: Subject: Re: IPv6 nodeinfo default behaviour From: =?UTF-8?B?56We5piO6YGU5ZOJ?= To: Loganaden Velvindron Content-Type: text/plain; charset=UTF-8 Cc: FreeBSD Net , bz@freebsd.org, gnn@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Jul 2014 18:25:43 -0000 At Tue, 22 Jul 2014 10:01:50 -0700, Loganaden Velvindron wrote: > > > Security Considerations > > > > > > This protocol has the potential of revealing information useful to a > > > would-be attacker. An implementation of this protocol MUST have a > > > default configuration that refuses to answer queries from global- > > > scope [3] addresses. > > > > > > I suggest that we switch to 0 by default to be more RFC compliant. > > > > Are you referring to the value of '(V_)icmp6_nodeinfo'? > > I'm referring to the sysctl: > > net.inet6.icmp6.nodeinfo. These two are essentially the same in this context: this sysctl is an interface to (V_)icmp6_nodeinfo. This variable is set to ICMP6_NODEINFO_FQDNOK|ICMP6_NODEINFO_NODEADDROK by default, and since ICMP6_NODEINFO_FQDNOK and ICMP6_NODEINFO_NODEADDROK are 0x1 and 0x2, respectively, the default value of the sysctl variable is 3 by default. In your original message, you said > > > I suggest that we switch to 0 by default to be more RFC compliant. and I tried to point out that it didn't make sense because "to be more RFC compliant" it doesn't have to switch to 0, it just needs to have the ICMP6_NODEINFO_GLOBALOK flag (0x8) cleared, and the current default meets the condition already. Now you're changing the reason: > I think that it's sensible to turn it to 0 by default, unless you need > it. Unlike being "RFC compliant", whether something is "sensible" is usually subjective, and different people may have different opinions. Personally, I often find "ping6 -w" quite useful for debugging purposes, and I think limiting its use to link-local by default gives a reasonable level of defense (and, disabling it by default would reduce the usability pretty much). So I'd rather prefer keeping the current default, but, again, other people may have a different preference. -- JINMEI, Tatuya