From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Singer Subject: Re: [RFC] ip / ifconfig redesign Date: Mon, 5 Dec 2005 09:40:10 -0800 Message-ID: <20051205174010.GA14101@buici.com> References: <200512022253.19029.a1426z@gawab.com> <200512031646.45332.a1426z@gawab.com> <4391E4FC.1040200@candelatech.com> <20051205140057.GC24764@tuxdriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: To: Ben Greear , Al Boldi , netdev@vger.kernel.org, linux-net@vger.kernel.org Content-Disposition: inline In-Reply-To: <20051205140057.GC24764@tuxdriver.com> Sender: linux-net-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, Dec 05, 2005 at 09:01:00AM -0500, John W. Linville wrote: > On Sat, Dec 03, 2005 at 10:33:32AM -0800, Ben Greear wrote: > > Al Boldi wrote: > > > > >Here specifically, ip/ifconfig is implemented upside-down requiring a > > >link/dev to exist for an address to be defined, in effect containing layer > > >3 inside layer 2, when an address should be allowed to be defined w/o a > > >link/dev much like an app is allowed to be defined w/o an address. > > > > [Removed lkml from CC list] > > > > You can add multiple virtual IP addresses to physical interfaces. It > > makes no sense to have an IP without any association to an interface > > in my opinion. Often, when you have multiple interfaces, you most > > definately > > want different IPs associated specifically with particular interfaces. > > Think about redundant paths, routers, firewalls, and such. > > The association between IP addresses and links is already a bit murky. > Reference the arp_announce sysctl for what I mean. I recall Dave M. > emphasizing on at least one occassion that IP addresses belong to > the _box_, not to the link. > > I think Al B.'s idea merits some consideration. I definitely think > we blur the distinctions between L2 and L3 a bit too much in places. > > Of course, patches would be helpful... Precisely the case. It should be the case that a box response to an arp on *any* interface for *any* IP address known to the box. As for changing the behavior, I haven't seen a compelling reason to change it. IMHO, without a motivating case, we would be mucking about without a clear goal.