All of lore.kernel.org
 help / color / mirror / Atom feed
From: Adrian Chung <adrian@enfusion-group.com>
To: lartc@vger.kernel.org
Subject: Re: [LARTC] Proxy ARP considered harmful. :)
Date: Sun, 24 Feb 2002 16:14:05 +0000	[thread overview]
Message-ID: <marc-lartc-101456736103932@msgid-missing> (raw)
In-Reply-To: <marc-lartc-101443755702421@msgid-missing>

On Sun, Feb 24, 2002 at 10:33:25AM +0100, bert hubert wrote:
> On Fri, Feb 22, 2002 at 11:11:44PM -0500, Adrian Chung wrote:
> > Here's my setup:
> > 
> >        .224 \
> >  
> >        .225  --- DSL Modem --- ISP (.252)
> > 
> >        .226 /

I've changed my setup slightly:
                                  
                                  DSL modem --- ISP (.128/25)
                                 /
          .226 -- .224-FW-.224 --
                                 \
                                  .225

I've altered the routes so that only .226 is routed to the left iface.

Here's the weirdness.

With a publishing ARP entry and proxy_arp set to '0' on the right hand
iface, .225 can resolve ARP queries for .226 without any problem every
time.

It always gets .224's MAC address.  This is good!

But, nothing at .128/25 seems to be able to reply to .226.

When I ping from .226 to say, .195, or even .252 which is the default
gateway, I get no response.  I don't even see ARP queries from those
boxes.

If I do an unsolicited ARPing to one of those boxes though, I can then
ping them from .226 for a short time, and I see ARP requests from
those boxes which are answered by my FW.  After a couple minutes, they
stop responding, and I never see any ARP requests for .226 again.  All
is fine if I do another unsolicited ARP.

My understanding is that if .195, .252 had an ARP entry in their cache
still for .226, they would use it, and send out another request to
make sure it's still valid.  If they don't have an entry, I would have
assumed they should have ARP'd for one again.

Anyways, I'm stumped!

--
Adrian Chung (adrian at enfusion-group dot com)
http://www.enfusion-group.com/~adrian
GPG Fingerprint: C620 C8EA 86BA 79CC 384C E7BE A10C 353B 919D 1A17
[toad.enfusion-group.com] up 22:46, 11 users, load average: 0.00

_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/lartc/

  parent reply	other threads:[~2002-02-24 16:14 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-02-23  4:11 [LARTC] Proxy ARP considered harmful. :) Adrian Chung
2002-02-24  9:33 ` bert hubert
2002-02-24 16:14 ` Adrian Chung [this message]
2002-02-24 20:06 ` Ard van Breemen
2002-02-24 20:49 ` Adrian Chung
2002-02-25  7:11 ` Ard van Breemen
2002-02-25 16:20 ` Adrian Chung

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=marc-lartc-101456736103932@msgid-missing \
    --to=adrian@enfusion-group.com \
    --cc=lartc@vger.kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.