From owner-freebsd-questions@FreeBSD.ORG Wed Feb 19 05:10:22 2014 Return-Path: Delivered-To: freebsd-questions@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 1B12EEE1 for ; Wed, 19 Feb 2014 05:10:22 +0000 (UTC) Received: from mail-ve0-f171.google.com (mail-ve0-f171.google.com [209.85.128.171]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id CA806188D for ; Wed, 19 Feb 2014 05:10:21 +0000 (UTC) Received: by mail-ve0-f171.google.com with SMTP id pa12so14326382veb.2 for ; Tue, 18 Feb 2014 21:10:15 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=rU0+1PSYGAaSupxgF5GoiQ4pJu8hmw+pOLOH3Xv9gVs=; b=ejahNVJu8IPmEhvAZJf8NMbwhcda+zKz9hQKjpIrmvVqFWDlA/+5jr9qxvim5h4HF8 MRNd4QKQ8L6f4RJAJ56grNx9EqUcKPcBIUyoBSNG7mdhMQot/xRZ3/KN5411oXVkaQ0k DPLUtTTSW7Y8dPddkFbb003Z3APEsJft4OQ6ddlVp2a3BVRJxysDulNhkJ8fxb5ugADg x3bCNP7CKDzqyuNRxFUY07YJm3MRSkLHl7CUP/QykFHbSKKFYvSSAw/qcQ4fOUVGBAnQ utbjHwIGRJ2rS32tD9EXxgc4p7j2tgE3cHJVSC1g9R4qpg6f7mdgPA60WFCw9H+Be4i5 +JPA== X-Gm-Message-State: ALoCoQldC63x6lUQXVRZKxps10KRZa2FvohVHWsZnNpvHqCByh11A9uT2mM9vWcgmG4yGwdNzlwv MIME-Version: 1.0 X-Received: by 10.220.188.10 with SMTP id cy10mr8278467vcb.36.1392786174153; Tue, 18 Feb 2014 21:02:54 -0800 (PST) Received: by 10.58.249.194 with HTTP; Tue, 18 Feb 2014 21:02:54 -0800 (PST) In-Reply-To: <3975.1392779391@server1.tristatelogic.com> References: <3975.1392779391@server1.tristatelogic.com> Date: Tue, 18 Feb 2014 21:02:54 -0800 Message-ID: Subject: Re: [SOLVED] Re: Semi-urgent: Disable NTP replies? From: Michael Sierchio To: "Ronald F. Guilmette" Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.17 Cc: FreeBSD Questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Feb 2014 05:10:22 -0000 One of the problems with UDP, and why NTP amplification attacks are so attractive, is that it is trivial to spoof the source address - you can't really know, without some higher-level protocol, where the initial packet came from. - M