From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Lew Pitcher Date: Sun, 26 Sep 2010 15:16:16 -0400 References: <201009262057.36382.lindner_marek@yahoo.de> <1285527477-10340-1-git-send-email-lindner_marek@yahoo.de> In-Reply-To: <1285527477-10340-1-git-send-email-lindner_marek@yahoo.de> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2919246.VuHoyJBvmj"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <201009261516.21774.lew.pitcher@digitalfreehold.ca> Subject: Re: [B.A.T.M.A.N.] batman-adv: softif lan loop avoidance 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 --nextPart2919246.VuHoyJBvmj Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On September 26, 2010 14:57:56 Marek Lindner wrote: > By connecting multiple batman-adv mesh nodes to the same LAN network > an ethernet loop can be created when the soft-interface is bridged > with the LAN interface. A simple visualization of the loop: > > node1 =A0<-- LAN =A0--> =A0node2 > =A0 =A0| =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | > =A0wifi =A0<-- mesh --> =A0wifi > > This patch adds the functionality to detect other batman-adv nodes > connected to the LAN and select a 'gateway' to talk to the > non-batman-adv devices on this LAN. All traffic from and to the mesh > will be handled by this gateway to avoid the loop. OGMs received via > the soft-interface are interpreted as 'port announcements' to locate > potential batman-adv nodes. The patch can also deal with vlans on > top of batX and offers a list of LAN neighbors via debugfs. Not meaning to "joggle your elbow" on this, and only for my own information= =20 and education, I wonder if you could tell me why this approach was selected? ISTM that, for this sort of loop,=20 node1 <-- LAN --> node2 | | wifi1 <-- mesh --> wifi2 you are trying to prevent OGMs from perpetually circulating around.=20 Wouldn't "wifi1" be able to recognize it's own OGMs? If so, then why wouldn= 't=20 it just drop them, rather than passing them along to the next node? If each wifi dropped it's own OGMs, then OGMs would only "circulate" once=20 through the loop, and be discarded when they arrive back at their originati= ng=20 node. Obviously, I don't understand enough about batman and batman-adv to be=20 critical of the design; I'm simply trying to understand how the design work= s,=20 and why you chose the "gateway" approach to eliminate routing loops. Thanks =2D-=20 Lew Pitcher Master Codewright & JOAT-in-training | Registered Linux User #112576 Me: http://pitcher.digitalfreehold.ca/ | Just Linux: http://justlinux.ca/ =2D--------- Slackware - Because I know what I'm doing. ------ --nextPart2919246.VuHoyJBvmj Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Armoured with GnuPG iEYEABECAAYFAkyfnAAACgkQagVFX4UWr65BGACeMCBFTuWbtG/5HD76CvS+Cx2d /fMAnjvLqf/ow3ZOI6FZqXSLEG/lU8iC =gUy8 -----END PGP SIGNATURE----- --nextPart2919246.VuHoyJBvmj--