From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Yx6cJ-0006Lp-HD for bitcoin-development@lists.sourceforge.net; Tue, 26 May 2015 04:37:27 +0000 X-ACL-Warn: Received: from resqmta-ch2-12v.sys.comcast.net ([69.252.207.44]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1Yx6cI-0001XK-B5 for bitcoin-development@lists.sourceforge.net; Tue, 26 May 2015 04:37:27 +0000 Received: from resomta-ch2-16v.sys.comcast.net ([69.252.207.112]) by resqmta-ch2-12v.sys.comcast.net with comcast id YUdM1q0012S2Q5R01UdM2X; Tue, 26 May 2015 04:37:21 +0000 Received: from crushinator.localnet ([IPv6:2601:6:4800:47f:1e4e:1f4d:332c:3bf6]) by resomta-ch2-16v.sys.comcast.net with comcast id YUdK1q0032JF60R01UdLaQ; Tue, 26 May 2015 04:37:20 +0000 From: Matt Whitlock To: Jim Phillips Date: Tue, 26 May 2015 00:37:18 -0400 Message-ID: <2916218.tfdjj1Sv9m@crushinator> User-Agent: KMail/4.14.8 (Linux/3.18.11-gentoo; KDE/4.14.8; x86_64; ; ) In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Spam-Score: 0.0 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [69.252.207.44 listed in list.dnswl.org] 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1Yx6cI-0001XK-B5 Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Zero-Conf for Full Node Discovery X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 May 2015 04:37:27 -0000 This is very simple to do. Just ping the "all nodes" address (ff02::1) and try connecting to TCP port 8333 of each node that responds. Shouldn't take but more than a few milliseconds on any but the most densely populated LANs. On Monday, 25 May 2015, at 11:06 pm, Jim Phillips wrote: > Is there any work being done on using some kind of zero-conf service > discovery protocol so that lightweight clients can find a full node on the > same LAN to peer with rather than having to tie up WAN bandwidth? > > I envision a future where lightweight devices within a home use SPV over > WiFi to connect with a home server which in turn relays the transactions > they create out to the larger and faster relays on the Internet. > > In a situation where there are hundreds or thousands of small SPV devices > in a single home (if 21, Inc. is successful) monitoring the blockchain, > this could result in lower traffic across the slow WAN connection. And > yes, I realize it could potentially take a LOT of these devices before the > total bandwidth is greater than downloading a full copy of the blockchain, > but there's other reasons to host your own full node -- trust being one. > > -- > *James G. Phillips IV* > > > > *"Don't bunt. Aim out of the ball park. Aim for the company of immortals." > -- David Ogilvy* > > *This message was created with 100% recycled electrons. Please think twice > before printing.*