Return-path: Received: from mail-io0-f169.google.com ([209.85.223.169]:43746 "EHLO mail-io0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751335AbdINVfq (ORCPT ); Thu, 14 Sep 2017 17:35:46 -0400 Received: by mail-io0-f169.google.com with SMTP id k101so4006830iod.0 for ; Thu, 14 Sep 2017 14:35:46 -0700 (PDT) Subject: Re: ROAM/CONNECT event with PORT_AUTHORIZED To: Ben Greear , Johannes Berg , Arend van Spriel , Arend van Spriel , Jouni Malinen Cc: Avraham Stern , linux-wireless References: <1505378361.31630.2.camel@sipsolutions.net> <1505389462.31630.6.camel@sipsolutions.net> <1505416658.31630.15.camel@sipsolutions.net> <9219316a-5556-6acf-30de-e9aa65a05706@gmail.com> <6d0ad07b-ca89-19a1-d3c2-ad94915b942a@candelatech.com> <5436d106-0b4a-9158-58bf-ff84b231cd19@candelatech.com> <8a26a838-adde-08f1-5f64-c98e1d947675@candelatech.com> <756be45c-fd13-56a7-b8d4-129c4fd07dc8@gmail.com> From: Denis Kenzior Message-ID: <5ec7a05e-dfa4-37e0-b108-51ca0885b9a7@gmail.com> (sfid-20170914_233549_925191_764B393B) Date: Thu, 14 Sep 2017 16:35:43 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi Ben, >> I think it is sane to assume that the IP address _should_ be the same. >> The 802.11 spec expects this even. This is to handle bizarre networks >> that don't do this >> properly. > > Can you point me to the section in the spec about this? > Lets see, 802.11-2012, Section 4.3.4.2: "The key concept is that the ESS network appears the same to an LLC layer as an IBSS network. STAs within an ESS may communicate and mobile STAs may move from one BSS to another (within the same ESS) transparently to LLC." Section 4.5.3.2, etc. >>> If not, how is this different from just re-doing DHCP like normal? >>> >> >> You get to use your old IP address. So e.g. your VoIP call doesn't >> disappear if you decide to switch access points. >> >>> And if so, you will in some cases be allowing duplicate IP addresses on >>> a network? >>> >> >> Life is never perfect ;) > > If you are breaking networks while trying to optimize something, then I > think you > are going about it wrong. > > Seems like we would need some way for the DHCP server and/or AP to > proactively > notify the station that they can skip DHCP, and default to not skipping. Not unless you're planning to extend the spec? 802.11 doesn't even mention DHCP in any real manner. > > I vaguely recall that FT had some way to verify you were roaming to the > same dhcp-domain > or not, but honestly, it has been a long time since I read through that... > Do you mean a mobility domain? This has nothing to do with DHCP... Regards, -Denis