From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Taylor Subject: Re: Awkward scenario: 3 interfaces and 3 devices with same ip/subnet. Date: Tue, 31 Aug 2010 10:25:57 -0500 Message-ID: <4C7D1F05.4050704@riverviewtech.net> References: <4C7D11F5.1010105@riverviewtech.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: netfilter-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Mail List - Netfilter On 08/31/10 09:49, Giacomo Bernardi wrote: > Doesn't seem to work, despite I created the arp entry with: > arp -s 10.2.0.1 00:11:22:33:44:55 The bogus IP will need to be in the same subnet to work. I.e. 10.0.0.11. > To be honest I'm not surprised: how is the receiver of those datagram > supposed to know they are for itself, since the dstip doesn't match > the IP of the local incoming interface? Sometimes it does, sometimes it doesn't. It really depends on how things are configured on the destination device. It's one of those "It might fail, but if it works, it's worth the 90 seconds it took to try it." things. I often use this when I'm configuring devices (APs) that all share the same IP address at initial configuration. I will set the MAC address in the ARP cache and then connect / configure as need. Grant. . . .