From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: UDP path MTU discovery Date: Thu, 25 Mar 2010 20:24:24 -0700 (PDT) Message-ID: <20100325.202424.201654947.davem@davemloft.net> References: <1269561751.2891.8.camel@ilion> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: gdt@gdt.id.au Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:40338 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753729Ab0CZDYH (ORCPT ); Thu, 25 Mar 2010 23:24:07 -0400 In-Reply-To: <1269561751.2891.8.camel@ilion> Sender: netdev-owner@vger.kernel.org List-ID: From: Glen Turner Date: Fri, 26 Mar 2010 10:32:31 +1030 > This differs from TCP, where it is the kernel -- and not > the application -- which organises retransmission. On > receiving a ICMP Fragmentation Needed the kernel can > immediately re-probe the path MTU wiht no waiting for > an exponential timer to expire. So the argument is, the kernel TCP does retransmission smart, userspace UDP apps do it stupidly, so let's turn off the feature instead of fixing userspace. Right? Sorry, fix this correctly in the user apps. Putting the blame on UDP path MTU discovery is placing it in the wrong spot.