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From: Kevin Greene <kgreenek@gmail.com>
Date: Mon, 25 May 2015 21:46:22 -0700
Message-ID: <CAEY8wq40vyG8CFZ7U1Z3hhF_ziSqEQ3GDpXLwm1MAVtK03aT-A@mail.gmail.com>
To: Matt Whitlock <bip@mattwhitlock.name>
Content-Type: multipart/alternative; boundary=089e013d1954181e9c0516f4d068
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Zero-Conf for Full Node Discovery
Precedence: list

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This is something you actually don't want. In order to make it as difficult
as possible for an attacker to perform a sybil attack, you want to choose a
set of peers that is as diverse, and unpredictable as possible.


On Mon, May 25, 2015 at 9:37 PM, Matt Whitlock <bip@mattwhitlock.name>
wrote:

> 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*
> > <https://plus.google.com/u/0/113107039501292625391/posts>
> > <http://www.linkedin.com/in/ergophobe>
> >
> > *"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.*
>
>
> ------------------------------------------------------------------------------
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> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
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--089e013d1954181e9c0516f4d068
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div class=3D"gmail_default" style=3D"color:#336666">This =
is something you actually don&#39;t want. In order to make it as difficult =
as possible for an attacker to perform a sybil attack, you want to choose a=
 set of peers that is as diverse, and unpredictable as possible.</div><div =
class=3D"gmail_default" style=3D"color:#336666"><br></div><div class=3D"gma=
il_extra"><br><div class=3D"gmail_quote">On Mon, May 25, 2015 at 9:37 PM, M=
att Whitlock <span dir=3D"ltr">&lt;<a href=3D"mailto:bip@mattwhitlock.name"=
 target=3D"_blank">bip@mattwhitlock.name</a>&gt;</span> wrote:<br><blockquo=
te class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc so=
lid;padding-left:1ex">This is very simple to do. Just ping the &quot;all no=
des&quot; address (ff02::1) and try connecting to TCP port 8333 of each nod=
e that responds. Shouldn&#39;t take but more than a few milliseconds on any=
 but the most densely populated LANs.<br>
<span><br>
<br>
On Monday, 25 May 2015, at 11:06 pm, Jim Phillips wrote:<br>
&gt; Is there any work being done on using some kind of zero-conf service<b=
r>
&gt; discovery protocol so that lightweight clients can find a full node on=
 the<br>
&gt; same LAN to peer with rather than having to tie up WAN bandwidth?<br>
&gt;<br>
&gt; I envision a future where lightweight devices within a home use SPV ov=
er<br>
&gt; WiFi to connect with a home server which in turn relays the transactio=
ns<br>
&gt; they create out to the larger and faster relays on the Internet.<br>
&gt;<br>
&gt; In a situation where there are hundreds or thousands of small SPV devi=
ces<br>
&gt; in a single home (if 21, Inc. is successful) monitoring the blockchain=
,<br>
&gt; this could result in lower traffic across the slow WAN connection.=C2=
=A0 And<br>
&gt; yes, I realize it could potentially take a LOT of these devices before=
 the<br>
&gt; total bandwidth is greater than downloading a full copy of the blockch=
ain,<br>
&gt; but there&#39;s other reasons to host your own full node -- trust bein=
g one.<br>
&gt;<br>
&gt; --<br>
</span>&gt; *James G. Phillips IV*<br>
&gt; &lt;<a href=3D"https://plus.google.com/u/0/113107039501292625391/posts=
" target=3D"_blank">https://plus.google.com/u/0/113107039501292625391/posts=
</a>&gt;<br>
&gt; &lt;<a href=3D"http://www.linkedin.com/in/ergophobe" target=3D"_blank"=
>http://www.linkedin.com/in/ergophobe</a>&gt;<br>
&gt;<br>
&gt; *&quot;Don&#39;t bunt. Aim out of the ball park. Aim for the company o=
f immortals.&quot;<br>
&gt; -- David Ogilvy*<br>
&gt;<br>
&gt;=C2=A0 *This message was created with 100% recycled electrons. Please t=
hink twice<br>
&gt; before printing.*<br>
<br>
---------------------------------------------------------------------------=
---<br>
One dashboard for servers and applications across Physical-Virtual-Cloud<br=
>
Widest out-of-the-box monitoring support with 50+ applications<br>
Performance metrics, stats and reports that give you Actionable Insights<br=
>
Deep dive visibility with transaction tracing using APM Insight.<br>
<a href=3D"http://ad.doubleclick.net/ddm/clk/290420510;117567292;y" target=
=3D"_blank">http://ad.doubleclick.net/ddm/clk/290420510;117567292;y</a><br>
_______________________________________________<br>
Bitcoin-development mailing list<br>
<a href=3D"mailto:Bitcoin-development@lists.sourceforge.net" target=3D"_bla=
nk">Bitcoin-development@lists.sourceforge.net</a><br>
<a href=3D"https://lists.sourceforge.net/lists/listinfo/bitcoin-development=
" target=3D"_blank">https://lists.sourceforge.net/lists/listinfo/bitcoin-de=
velopment</a><br>
</blockquote></div><br></div></div>

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