From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Carlos Velasco <carlosev@newipnet.com>
Cc: Lamont Granquist <lamont@scriptkiddie.org>,
Bill Davidsen <davidsen@tmr.com>,
"David S. Miller" <davem@redhat.com>,
bloemsaa@xs4all.nl, Marcelo Tosatti <marcelo@conectiva.com.br>,
netdev@oss.sgi.com, linux-net@vger.kernel.org, layes@loran.com,
torvalds@osdl.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [2.4 PATCH] bugfix: ARP respond on all devices
Date: 17 Aug 2003 14:38:06 +0100 [thread overview]
Message-ID: <1061127485.21878.32.camel@dhcp23.swansea.linux.org.uk> (raw)
In-Reply-To: <200308171509570955.003E4FEC@192.168.128.16>
On Sul, 2003-08-17 at 14:09, Carlos Velasco wrote:>
> >I can only think of one scenario where an arp request would come in
> from
> >192.168.140.x to a router interface that has 192.168.128.1. That one
> >scenario is a misconfiguration.
Two virtual networks sharing the same lan is a perfectly valid one.
There since the router doesn't know how to reach 140.x it wouldnt reply,
if it also *is* 140.1 for example then it can reply if it wishes but I
see nothing in 826 requiring it does. In normal situations the routing
tables will indicate preferred routes and gateways.
> >I believe that reason we do the sanity check is because of basic IP
> >routing. If the source is not from an IP address on the interface we
> >received it on, we cannot reply to that IP address. It is simple as
> that.
Thats not true at the IP level for basic situations like asymmetric
routing.
> >As I stated, ARP is designed to be used on a LAN. This means that all
> >stations that send/receive ARP packets are on the same subnet. This
> is
> >the reason we do the check.
Actual ARP is used on everything from 300 baud radio networks up
> >correctly. There is no case where a properly configured host should
> ever
> >send a ARP request for an IP address on a different subnet.
See above, multiple virtual networks.
> >not on the same network, then the host/router/client needs to find the
> >gateway which is on the local network
See "both are my address" case above
> >Basic and proper implementations of the TCP/IP stack should never ARP
> out
> >for a device that it is not located on the same logical network the
> host
> >is, the reason for this being they cannot communicate directly unless
See above, multiple lans co-existing.
> >I hope this clears up the reson why Cisco's ARP implementation has
> this
> >safeguard you have found along with several others, HOWEVER, please
> refer
> >to RFC 1027, (http://www.ietf.org/rfc/rfc1027.txt) and under section
> 2.4,
> >it contains the following paragraph:
RFC1027 covers proxy ARP only
next prev parent reply other threads:[~2003-08-17 13:42 UTC|newest]
Thread overview: 168+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-07-27 20:52 [2.4 PATCH] bugfix: ARP respond on all devices Bas Bloemsaat
2003-07-27 22:12 ` David S. Miller
2003-07-28 2:31 ` Ben Greear
2003-07-28 7:33 ` Bas Bloemsaat
2003-07-27 23:40 ` Carlos Velasco
2003-07-27 23:46 ` David S. Miller
2003-07-27 23:58 ` Carlos Velasco
2003-07-27 23:58 ` David S. Miller
2003-07-28 0:11 ` Carlos Velasco
2003-07-28 0:14 ` David S. Miller
2003-07-28 0:35 ` Carlos Velasco
2003-07-28 0:36 ` David S. Miller
2003-07-28 0:53 ` Carlos Velasco
2003-07-28 0:55 ` David S. Miller
2003-07-28 1:23 ` Carlos Velasco
2003-07-28 1:35 ` David S. Miller
2003-07-28 10:43 ` Carlos Velasco
2003-07-28 17:09 ` Phil Oester
2003-07-28 18:56 ` Bas Bloemsaat
2003-07-28 4:37 ` David Lang
2003-07-28 4:39 ` David S. Miller
2003-07-28 10:49 ` Carlos Velasco
2003-07-28 0:57 ` Assorted 2.6.0-test2 build warnings J.C. Wren
2003-07-28 22:11 ` Randy.Dunlap
2003-07-29 10:42 ` Adrian Bunk
2003-07-29 2:51 ` [2.4 PATCH] bugfix: ARP respond on all devices Bill Davidsen
2003-07-29 4:48 ` Lamont Granquist
2003-08-04 6:10 ` Pekka Savola
2003-08-17 13:09 ` Carlos Velasco
2003-08-17 13:16 ` Carlos Velasco
2003-08-17 13:41 ` Alan Cox
2003-08-17 13:55 ` Carlos Velasco
2003-08-17 15:12 ` Bernd Eckenfels
2003-08-17 15:28 ` Alan Cox
2003-08-17 15:57 ` Bas Bloemsaat
2003-08-17 15:59 ` Carlos Velasco
2003-08-17 16:26 ` Alan Cox
2003-08-17 16:27 ` Carlos Velasco
2003-08-17 17:24 ` Alan Cox
2003-08-17 22:48 ` Willy Tarreau
2003-08-18 5:22 ` David S. Miller
2003-08-18 6:56 ` Willy Tarreau
2003-08-18 7:01 ` David S. Miller
2003-08-18 7:29 ` Willy Tarreau
2003-08-18 7:43 ` Willy Tarreau
2003-08-18 5:31 ` David S. Miller
2003-08-18 11:39 ` Stephan von Krawczynski
2003-08-18 11:44 ` David S. Miller
2003-08-18 12:34 ` Stephan von Krawczynski
2003-08-18 12:30 ` David S. Miller
2003-08-18 12:51 ` Mr. James W. Laferriere
2003-08-18 12:53 ` Stephan von Krawczynski
2003-08-18 12:55 ` David S. Miller
2003-08-18 13:17 ` Stephan von Krawczynski
2003-08-18 13:14 ` David S. Miller
2003-08-18 14:23 ` Stephan von Krawczynski
2003-08-18 14:19 ` David S. Miller
2003-08-18 15:46 ` Stephan von Krawczynski
2003-08-18 13:23 ` jamal
2003-08-18 13:21 ` David S. Miller
2003-08-18 13:40 ` Stephan von Krawczynski
2003-08-20 6:55 ` Bas Bloemsaat
2003-08-18 21:54 ` Bill Davidsen
2003-08-18 13:40 ` Dominik Kubla
2003-08-18 12:51 ` Willy Tarreau
2003-08-18 12:53 ` David S. Miller
2003-08-18 14:28 ` Willy Tarreau
2003-08-18 14:28 ` David S. Miller
2003-08-18 12:08 ` Bas Bloemsaat
2003-08-18 12:03 ` David S. Miller
2003-08-18 21:32 ` Bill Davidsen
2003-08-19 3:21 ` Ben Greear
2003-08-19 15:22 ` David S. Miller
2003-08-19 7:58 ` Bas Bloemsaat
2003-08-18 15:49 ` SRC IP selection in ARP request (Was: bugfix: ARP respond on all devices) Vladimir B. Savkin
2003-08-17 16:51 ` [2.4 PATCH] bugfix: ARP respond on all devices David T Hollis
2003-08-17 16:45 ` Carlos Velasco
2003-08-17 17:13 ` Arjan van de Ven
2003-08-17 19:46 ` insecure
2003-08-18 5:11 ` David S. Miller
2003-08-18 5:29 ` David S. Miller
2003-08-17 13:59 ` Bas Bloemsaat
2003-08-18 10:48 ` Robert Collier
2003-08-17 13:38 ` Alan Cox [this message]
[not found] <e2Yb.5CB.17@gated-at.bofh.it>
[not found] ` <e43Y.6x0.17@gated-at.bofh.it>
[not found] ` <e43Y.6x0.19@gated-at.bofh.it>
[not found] ` <e43Y.6x0.21@gated-at.bofh.it>
[not found] ` <e43Y.6x0.23@gated-at.bofh.it>
[not found] ` <e43Y.6x0.25@gated-at.bofh.it>
[not found] ` <e43Y.6x0.15@gated-at.bofh.it>
[not found] ` <e4nd.6K9.5@gated-at.bofh.it>
[not found] ` <e4ne.6K9.11@gated-at.bofh.it>
[not found] ` <e4x3.6RV.23@gated-at.bofh.it>
[not found] ` <e4Qe.7cR.3@gated-at.bofh.it>
[not found] ` <e503.7kj.23@gated-at.bofh.it>
[not found] ` <e5jh.7yW.5@gated-at.bofh.it>
[not found] ` <edJU.6nT.25@gated-at.bofh.it>
2003-07-28 20:45 ` Julien Oster
2003-08-19 12:02 Richard Underwood
2003-08-19 12:35 ` Alan Cox
2003-08-19 18:30 ` Daniel Gryniewicz
2003-08-19 18:29 ` David S. Miller
2003-08-19 19:12 ` Daniel Gryniewicz
2003-08-19 19:10 ` David S. Miller
2003-08-20 16:49 ` Bill Davidsen
2003-08-20 17:00 ` David S. Miller
2003-08-20 17:44 ` Ben Greear
2003-08-20 17:48 ` David S. Miller
2003-08-20 23:18 ` Julian Anastasov
2003-08-23 20:50 ` Bill Davidsen
2003-08-20 19:08 ` Bill Davidsen
2003-08-20 20:07 ` Bas Bloemsaat
2003-08-19 19:42 ` bill davidsen
2003-08-19 13:11 ` Bas Bloemsaat
2003-08-19 15:34 ` David S. Miller
2003-08-19 17:39 ` Lars Marowsky-Bree
2003-08-19 17:36 ` David S. Miller
2003-08-19 21:01 ` Harley Stenzel
2003-08-19 16:19 ` Stephan von Krawczynski
2003-08-19 16:54 ` David S. Miller
2003-08-19 17:15 ` Stephan von Krawczynski
2003-08-19 16:56 ` David S. Miller
2003-08-19 14:34 Richard Underwood
2003-08-19 14:54 ` Willy Tarreau
2003-08-19 15:07 ` Stephan von Krawczynski
2003-08-19 15:57 ` David S. Miller
2003-08-19 16:52 ` Stephan von Krawczynski
2003-08-19 16:53 ` David S. Miller
2003-08-19 17:12 ` Stephan von Krawczynski
2003-08-19 17:09 ` David S. Miller
2003-08-19 19:04 ` Alan Cox
2003-08-19 19:01 ` David S. Miller
2003-08-19 19:19 ` Bas Bloemsaat
2003-08-19 19:16 ` David S. Miller
2003-08-20 8:49 ` Roman Pletka
2003-08-20 14:15 ` Stephan von Krawczynski
2003-08-20 14:43 ` Roman Pletka
2003-08-20 15:55 ` Stephan von Krawczynski
2003-08-20 16:47 ` Roman Pletka
2003-08-19 15:53 ` Bill Davidsen
2003-08-19 16:14 ` David S. Miller
2003-08-19 17:17 ` Bill Davidsen
2003-08-19 19:08 ` Alan Cox
2003-08-19 21:53 ` Stephan von Krawczynski
2003-08-19 16:54 Richard Underwood
2003-08-19 16:51 ` David S. Miller
2003-08-19 17:10 ` Stephan von Krawczynski
2003-08-19 17:07 ` David S. Miller
2003-08-19 19:57 ` bill davidsen
2003-08-19 17:56 Richard Underwood
2003-08-19 17:53 ` David S. Miller
2003-08-19 18:05 Richard Underwood
2003-08-19 18:21 ` David S. Miller
2003-08-20 12:52 ` Harley Stenzel
2003-08-19 18:16 Richard Underwood
2003-08-19 18:13 ` David S. Miller
2003-08-19 18:30 ` Bas Bloemsaat
[not found] <mdtk.Zy.1@gated-at.bofh.it>
[not found] ` <mgUv.3Wb.39@gated-at.bofh.it>
[not found] ` <mgUv.3Wb.37@gated-at.bofh.it>
[not found] ` <miMw.5yo.31@gated-at.bofh.it>
2003-08-19 18:48 ` Andi Kleen
2003-08-19 19:17 ` Daniel Gryniewicz
2003-08-19 19:21 ` Andi Kleen
2003-08-19 19:27 ` Daniel Gryniewicz
2003-08-19 19:24 ` David S. Miller
2003-08-19 19:32 ` Andi Kleen
2003-08-19 19:28 ` David S. Miller
2003-08-20 9:53 ` Alan Cox
2003-08-20 15:41 ` Stephan von Krawczynski
2003-08-20 15:38 ` David S. Miller
2003-08-19 19:38 ` Valdis.Kletnieks
2003-08-19 19:37 ` David S. Miller
2003-08-19 20:44 ` Valdis.Kletnieks
2003-08-19 19:00 Richard Underwood
2003-08-19 18:58 ` David S. Miller
[not found] <mfYi.374.31@gated-at.bofh.it>
[not found] ` <mkbE.6Rk.35@gated-at.bofh.it>
2003-08-19 20:00 ` Andi Kleen
2003-08-19 19:56 ` David S. Miller
2003-08-19 22:12 Richard Underwood
2003-08-19 22:11 ` David S. Miller
2003-08-19 23:15 ` Stephan von Krawczynski
2003-08-20 8:58 Richard Underwood
2003-08-20 15:23 ` jamal
2003-08-20 15:28 ` jamal
2003-08-20 20:10 Richard Underwood
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1061127485.21878.32.camel@dhcp23.swansea.linux.org.uk \
--to=alan@lxorguk.ukuu.org.uk \
--cc=bloemsaa@xs4all.nl \
--cc=carlosev@newipnet.com \
--cc=davem@redhat.com \
--cc=davidsen@tmr.com \
--cc=lamont@scriptkiddie.org \
--cc=layes@loran.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-net@vger.kernel.org \
--cc=marcelo@conectiva.com.br \
--cc=netdev@oss.sgi.com \
--cc=torvalds@osdl.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).