From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4AB29DDF.3050303@tiwoc.de> Date: Thu, 17 Sep 2009 22:36:47 +0200 From: Daniel Seither MIME-Version: 1.0 References: <8c906fa50909171115v2b296844h69c5f93eea99403c@mail.gmail.com> <4AB28C2D.7060600@tiwoc.de> <8c906fa50909171314lb275b23vf87bd2852e3bd244@mail.gmail.com> In-Reply-To: <8c906fa50909171314lb275b23vf87bd2852e3bd244@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [B.A.T.M.A.N.] IP from MAC Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: The list for a Better Approach To Mobile Ad-hoc Networking Gustavo Lindberg schrieb: > 2009/9/17 Daniel Seither > >> Gustavo Lindberg wrote: >>> Then, At a meeting of 60 people there is the 99% probability of the >> least >>> two men have a birthday the same day. So,, Similarly to the case of >>> MAC-Adress is: >>> >>> P(r)=1-65536!/(65536^r * (65536-r)!) >> Robin uses 3 bytes of the MAC address to choose the IP address of the >> mesh interface, not only 2 bytes = 65536 possibilities. This leads to >> 2^24 = 16777216 different addresses. >> > > All IP addresses are derived by device's MAC address, if MAC is > aa:bb:cc:dd:ee:ff then ath0 IP (mesh iface) will be 5.dd:ee:ff while ath1 IP > and ath2 IP will be 101.ee:ff:1 and 102.ee:ff:1 (obviously in decimal > format). I read this before, but now I realize that colliding IP addresses of the ath1/2 interfaces are a problem. This seriously limits the number of nodes in the network for reasonably low collision probabilities. With 200 nodes, you already have a probability greater than 25%. Enter IPv6... Regards, Daniel