From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Paasch Subject: Re: [PATCH net-next] IPv6: enable TCP to use an anycast address Date: Sat, 11 Jan 2014 14:46:59 +0100 Message-ID: <20140111134659.GC4698@cpaasch-mac> References: <1389445570.24657.YahooMailBasic@web125502.mail.ne1.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Alexey Kuznetsov , netdev@vger.kernel.org, Hannes Frederic Sowa , "David S. Miller" , James Morris , Hideaki Yoshifuji , Patrick McHardy To: =?iso-8859-1?Q?Fran=E7ois-Xavier?= Le Bail Return-path: Received: from smtp.sgsi.ucl.ac.be ([130.104.5.67]:51157 "EHLO smtp5.sgsi.ucl.ac.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751343AbaAKNrI (ORCPT ); Sat, 11 Jan 2014 08:47:08 -0500 Content-Disposition: inline In-Reply-To: <1389445570.24657.YahooMailBasic@web125502.mail.ne1.yahoo.com> Sender: netdev-owner@vger.kernel.org List-ID: On 11/01/14 - 05:06:10, Fran=E7ois-Xavier Le Bail wrote: > On Sat, 1/11/14, Alexey Kuznetsov wrote: > As said in http://tools.ietf.org/html/draft-iab-anycast-arch-implicat= ions-12.html#section-2.1 > (this informational draft is in RCF queue) This draft does not say that TCP should be used with anycast addresses. Rather the opposite: " This document does not treat in any depth the fact that there are deployed services with TCP transport using anycast today. Evidence exists to suggest that such practice is not "safe" in the traditional and architectural sense (as described in Section 4.2). " And Section 4.2 gives more information. http://tools.ietf.org/html/draft-iab-anycast-arch-implications-12.html#= section-4.2 Christoph >=20 > " No firm conclusion was reached regarding > use of TCP with anycasted services, but it was observed that > anycasting was useful for DNS, although it did introduce some new > complexities." >=20 > For this works, there is need for appropriate routing (BGP, ...). >=20 > Many DNS root-servers use TCP with anycast (IPv4 and IPV6). >=20 > see : http://tools.ietf.org/html/draft-jabley-dnsop-anycast-mapping-0= 4#section-4 >=20 > " L-Root service is provided using a single IPv4 address (199.7.83.= 42) > and a single IPv6 address (2001:500:3::42). It should be noted th= at > it is preferable to refer to the service using its DNS name (L.ROO= T- > SERVERS.NET) rather than literal addresses, since addresses can > change from time to time." >=20 > Fran=E7ois-Xavier Le Bail > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html