Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1QoYJB-0004TQ-6E for bitcoin-development@lists.sourceforge.net; Wed, 03 Aug 2011 10:04:13 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.160.175 as permitted sender) client-ip=209.85.160.175; envelope-from=mh.in.england@gmail.com; helo=mail-gy0-f175.google.com; Received: from mail-gy0-f175.google.com ([209.85.160.175]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-MD5:128) (Exim 4.76) id 1QoYJA-00069v-8o for bitcoin-development@lists.sourceforge.net; Wed, 03 Aug 2011 10:04:13 +0000 Received: by mail-gy0-f175.google.com with SMTP id 4so57289gyg.34 for ; Wed, 03 Aug 2011 03:04:12 -0700 (PDT) MIME-Version: 1.0 Received: by 10.142.214.9 with SMTP id m9mr4521059wfg.177.1312365851601; Wed, 03 Aug 2011 03:04:11 -0700 (PDT) Sender: mh.in.england@gmail.com Received: by 10.68.44.71 with HTTP; Wed, 3 Aug 2011 03:04:11 -0700 (PDT) Date: Wed, 3 Aug 2011 12:04:11 +0200 X-Google-Sender-Auth: 7wP3IY_1imnLpq-pG8OhLl0jTo0 Message-ID: From: Mike Hearn To: Bitcoin Dev Content-Type: multipart/alternative; boundary=000e0cd2e07a6669d604a996fc7e X-Spam-Score: 1.4 (+) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (mh.in.england[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.7 URIBL_WS_SURBL Contains an URL listed in the WS SURBL blocklist [URIs: bitcoin.org.uk] 1.0 HTML_MESSAGE BODY: HTML included in message 0.3 HTML_FONT_FACE_BAD BODY: HTML font face is not a word 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: 1QoYJA-00069v-8o Subject: [Bitcoin-development] DNS seeds returning gone peers 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: Wed, 03 Aug 2011 10:04:13 -0000 --000e0cd2e07a6669d604a996fc7e Content-Type: text/plain; charset=UTF-8 This is expected to happen from time to time of course as it's inherently racy, but there are a *lot* of bad nodes appearing in the DNS seeds. $ nmap -oG /tmp/x -p 8333 `dig +short bitseed.bitcoin.org.uk dnsseed.bluematt.me bitseed.xf2.org` ... Nmap done: 48 IP addresses (25 hosts up) scanned in 9.80 seconds $ grep -c 'closed' /tmp/x 6 So of 48 IPs returned only 19 are actually usable. This is slowing down peer bringup for the Android apps, which don't currently save the addresses of last-used peers (yes, I know we should fix this). I was talking to a friend a few days ago about Bitcoin, he seemed interested. I'm hoping he might take on DNS seeding as a project. A custom DNS server that watches the network to find long-lived peers that run the latest version would be helpful for resolving this kind of thing. --000e0cd2e07a6669d604a996fc7e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable This is expected to happen from time to time of course as it's inherent= ly racy, but there are a lot=C2=A0of bad nodes appearing in the DNS = seeds.

$ nmap -oG /tmp/x -p 8333 `dig +short= bitseed.bitcoin.org.uk dnsseed.bluematt.me bitseed.xf2.org`
...
Nmap done: 48 IP addresses (25 h= osts up) scanned in 9.80 seconds

$ grep -c 'closed' /tmp/x
6

So of 48 IPs returned only 19 are actually = usable. This is slowing down peer bringup for the Android apps, which don&#= 39;t currently save the addresses of last-used peers (yes, I know we should= fix this).

I was talking to a friend a few days ago about Bitcoin,= he seemed interested. I'm hoping he might take on DNS seeding as a pro= ject. A custom DNS server that watches the network to find long-lived peers= that run the latest version would be helpful for resolving this kind of th= ing.
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