From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1MJnrq-0002bM-3v for garchives@archives.gentoo.org; Thu, 25 Jun 2009 12:15:50 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 1E198E03DE; Thu, 25 Jun 2009 12:15:49 +0000 (UTC) Received: from smtpout.karoo.kcom.com (smtpout.karoo.kcom.com [212.50.160.34]) by pigeon.gentoo.org (Postfix) with ESMTP id D538FE03DE for ; Thu, 25 Jun 2009 12:15:48 +0000 (UTC) X-IronPort-AV: E=Sophos;i="4.42,289,1243810800"; d="scan'208";a="110435983" Received: from unknown (HELO compaq.stroller.uk.eu.org) ([213.152.39.90]) by smtpout.karoo.kcom.com with ESMTP; 25 Jun 2009 13:15:48 +0100 Received: from [192.168.1.71] (unknown [192.168.1.71]) by compaq.stroller.uk.eu.org (Postfix) with ESMTP id 70E08134B0D for ; Thu, 25 Jun 2009 13:15:45 +0100 (BST) Message-Id: <5404EBD4-8B15-4706-B349-AE5EAA4C753D@stellar.eclipse.co.uk> From: Stroller To: gentoo-user@lists.gentoo.org In-Reply-To: <5602B0BD6D59AE4791BE83104940118DC2F3DB7D@excprdmbxw002.optus.com.au> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 (Apple Message framework v935.3) Subject: Re: [gentoo-user] Machine doesn't respond to broadcast ping. Date: Thu, 25 Jun 2009 13:15:44 +0100 References: <5602B0BD6D59AE4791BE83104940118DC2F3DB7D@excprdmbxw002.optus.com.au> X-Mailer: Apple Mail (2.935.3) X-Archives-Salt: e54f96eb-2fce-4f4f-b829-76218bfdc96a X-Archives-Hash: 91a0cd1c239a2e41fd5cb5068e7edd99 On 25 Jun 2009, at 08:10, Adam Carter wrote: >>> I've got one machine here on the LAN which isn't responding to >>> broadcast >>> ping. Any idea why not? >> >> You need to set icmp_echo_ignore_broadcasts to 0. Default is >> 1, mainly for dos prevention: >> >> # sysctl net.ipv4.icmp_echo_ignore_broadcasts=0 > > I thought it would default to off in most OSes these days, because of; > http://en.wikipedia.org/wiki/Smurf_attack > > Are those other machines patched up? They're all on the LAN, anyway, but: 192.168.1.71 - the machine from which the ping was sent (don't know if that makes a difference). Mac OS X 10.5, fairly recent updates, but perhaps not this month's. 192.168.1.43 - Gentoo 1.4 profile, 2.4 kernel, not updated in at least 3 years, well due for retirement, just as soon as I've moved services to 192.168.1.100 192.168.1.22 - network KVM [1], probably can't get a firmware update, unfortunately. :( Not a very recent one, anyway. Although they may still sell it, I'm pretty sure it's rebadged OEM & development on the product is ceased. 192.168.1.9 - LaserJet 4000, JetDirect card. Interestingly the router is a model at least 5 years old - a Draytek Vigor, older than the 192.168.1.43 build - and it isn't replying. I now realise that 3 other Linux boxes are missing from the list. I'm sure I'm not the only person on the list to occasionally lose count. Anyway, for each device it's either a case of: - yes, it's regularly updated; - sorry, there's not much to be done about it; or - yes, I know it needs updating! It shouldn't matter, anyway, if they're all behind a NAT router, should it? I'm inclined to disable this ignore, because I do find broadcast ping very occasionally useful. Stroller. [1] http://www.austin-hughes.co.uk/products.cfm?Product=28