From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] lwt: fix rx checksum setting for lwt devices tunneling over ipv6 Date: Tue, 16 Feb 2016 16:37:50 -0500 (EST) Message-ID: <20160216.163750.631056934356631230.davem@davemloft.net> References: <20160216.155332.104228217048445468.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: tgraf@suug.ch, pabeni@redhat.com, jbenc@redhat.com, pshelar@nicira.com, jesse@kernel.org, netdev@vger.kernel.org To: tom@herbertland.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:40454 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932865AbcBPVhy (ORCPT ); Tue, 16 Feb 2016 16:37:54 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Tom Herbert Date: Tue, 16 Feb 2016 13:31:34 -0800 > On Feb 16, 2016 12:53 PM, "David Miller" wrote: >> And practically speaking we disappear from the internet for VXLAN tunnel >> endpoints implementing the VXLAN spec properly. >> >> That's not going to help anyone at all. > > A lot of effort has gone into defining the constraints for using zero udp6 > csum (look at Rfc6935 and rfc6936). Just because Cisco unilaterally decided > the csum is a nuisance, doesn't mean it can be ignored. No udp6 csum > increases chance of misdelivery, which in multitenant nv is really bad. People who review RFCs had ample opportunity to review the VXLAN RFC and find this issue and fix it. It slipped through and now we are stuck with it, just like we are stuck with bad user facing kernel APIs. Objecting now and voicing our objection by breaking interoperability serves no useful purpose whatsoever.