From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: [RFC] ip / ifconfig redesign Date: Mon, 05 Dec 2005 14:28:33 -0800 Message-ID: <4394BF11.2070205@hp.com> References: <200512022253.19029.a1426z@gawab.com> <200512031646.45332.a1426z@gawab.com> <4391E4FC.1040200@candelatech.com> <20051205140057.GC24764@tuxdriver.com> <20051205174010.GA14101@buici.com> <43947FEB.7020504@unfix.org> <4394BCD5.1060505@psc.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Jeroen Massar , Marc Singer , Ben Greear , Al Boldi , netdev@vger.kernel.org, linux-net@vger.kernel.org Return-path: To: John Heffner In-Reply-To: <4394BCD5.1060505@psc.edu> Sender: linux-net-owner@vger.kernel.org List-Id: netdev.vger.kernel.org John Heffner wrote: > Jeroen Massar wrote: > >> I wonder how many RFC's it violates. An interface must only answer ARP's >> on the interface that it is configured on, not anything else. > > > Not true. See RFC 1122, section 3.3.4. The standard leaves this > decision up to the implementation, for good reason. > > From 1122 (note the use of MAY, not MUST or SHOULD): > " > There are two key requirement issues related to multihoming: > > (A) A host MAY silently discard an incoming datagram whose > destination address does not correspond to the physical > interface through which it is received. > > (B) A host MAY restrict itself to sending (non-source- > routed) IP datagrams only through the physical > interface that corresponds to the IP source address of > the datagrams. > " That's the discussion related to things like the "Strong ES" (end system) model right? As such, isn't that discussing what _IP_ may do rather than what ARP may do? 1122 doesn't say much about the interfaces/MAC's that should be part of a given ARP reply. ARP seems to be RFC 826 and probably others, and the algorithm described in 826 doesn't seem to be specific on the topic of interfaces - at least not to my really brief read. rick jones