Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757007Ab2EVQsN (ORCPT ); Tue, 22 May 2012 12:48:13 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:43321 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752999Ab2EVQsK (ORCPT ); Tue, 22 May 2012 12:48:10 -0400 Subject: Re: tcp timestamp issues with google servers From: Eric Dumazet To: Vijay Subramanian Cc: Miklos Szeredi , netdev@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: <87r4ujno34.fsf@tucsk.pomaz.szeredi.hu> <1337278363.3403.39.camel@edumazet-glaptop> <87zk90s0em.fsf@tucsk.pomaz.szeredi.hu> <1337701259.3361.208.camel@edumazet-glaptop> <87mx50rz34.fsf@tucsk.pomaz.szeredi.hu> Content-Type: text/plain; charset="UTF-8" Date: Tue, 22 May 2012 18:48:05 +0200 Message-ID: <1337705285.3361.229.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 836 Lines: 29 On Tue, 2012-05-22 at 09:38 -0700, Vijay Subramanian wrote: > > Okay. Is there a way to find out whether there is a middlebox or not? > > > > Miklos, > Maybe tcptraceroute[1] can help you figure this out. > > Hope this helps. > Vijay > > [1] http://michael.toren.net/code/tcptraceroute/ The transparent proxy can intercept TCP connections to port 80/443, and let ICMP being NATed by the box. So its better to check of the delay between SYN and SYNACK is roughly independent of the HTTP server. If you have very large range of delays, you can conclude its not a transparent proxy. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/