From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751717AbdJTGPy (ORCPT ); Fri, 20 Oct 2017 02:15:54 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:33064 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751093AbdJTGPw (ORCPT ); Fri, 20 Oct 2017 02:15:52 -0400 Date: Fri, 20 Oct 2017 07:15:48 +0100 (WEST) Message-Id: <20171020.071548.524144466372098011.davem@davemloft.net> To: mgamal@redhat.com Cc: netdev@vger.kernel.org, skhare@vmware.com, pv-drivers@vmware.com, linux-kernel@vger.kernel.org, cavery@redhat.com, otubo@redhat.com, vkuznets@redhat.com Subject: Re: [PATCH] vmxnet3: Use correct minimum MTU value From: David Miller In-Reply-To: <1508250823-1954-1-git-send-email-mgamal@redhat.com> References: <1508250823-1954-1-git-send-email-mgamal@redhat.com> X-Mailer: Mew version 6.7 on Emacs 25.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 19 Oct 2017 23:15:52 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mohammed Gamal Date: Tue, 17 Oct 2017 16:33:43 +0200 > Currently the vmxnet3 driver has a minimum MTU value of 60. Which > goes against the RFC791 spec which specifies it at 68. > > Setting MTU to values between 60 <= MTU <= 67 causes the network > interface to lose its IP, and it fails to restart. > > This sets the minimum value to ETH_MIN_MTU (68) which is compatible > with is according to spec. > > Reported-by: Bo Yang > Signed-off-by: Mohammed Gamal There are protocols other than IPv4, and as Andrew mentioned the ipv4 stack does the right thing by disabling ipv4 on an interface when the MTU is too small.