Subject: RE: [2.4 PATCH] bugfix: ARP respond on all devices
From: jamal <hadi@cyberus.ca>
Reply-To: hadi@cyberus.ca
To: Richard Underwood <richard@aspectgroup.co.uk>
Cc: "'David S. Miller'" <davem@redhat.com>,
       Alan Cox <alan@lxorguk.ukuu.org.uk>, skraw@ithnet.com, willy@w.ods.org,
       carlosev@newipnet.com, lamont@scriptkiddie.org, davidsen@tmr.com,
       bloemsaa@xs4all.nl, marcelo@conectiva.com.br, netdev@oss.sgi.com,
       linux-net@vger.kernel.org, layes@loran.com, torvalds@osdl.org,
       linux-kernel@vger.kernel.org
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References: <353568DCBAE06148B70767C1B1A93E625EAB61@post.pc.aspectgroup.co.uk>
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Date: 20 Aug 2003 11:23:31 -0400
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What Dave meant is the state machine used in 2461 for IPV6 is actually
used in v4 as well. There is no equivalent RFC that is valid for IPv4.
Maybe one can be written (fire! fire! where are the firemen?).

for V6 (ndisc not ARP) check the validation tests the usagi people have
been doing against 2461.

cheers,
jamal

On Wed, 2003-08-20 at 04:58, Richard Underwood wrote:
> David S. Miller wrote:
> > 
> > Indeed, would people stop quoting from RFC 985 and
> > RFC 826.
> 
> 	In case anyone missed it, the following message was posted to
> linux-net and netdev. This is currently a draft standard, but anyone
> implementing IPv6 should be following it. It clearly states that the the
> source address for the equivalent of the ARP request should be the INTERFACE
> address.
> 
> 	While it doesn't directly apply to IPv4 (except for David's claim
> that IPv4 ARP is based on IPv6 ARP) it does clarify the situation nicely.
> 
> 	I, for one, will be glad when (!) we all migrade to IPv6 and we can
> once and all be done with this nonsense, unless Linux plans to deviate from
> the standard?
> 
> 	Thanks,
> 
> 		Richard
> 
> -----Original Message-----
> From: Steven Blake [mailto:slblake@petri-meat.com]
> Sent: 20 August 2003 05:58
> To: David S. Miller
> Cc: netdev@oss.sgi.com; linux-net@vger.kernel.org
> Subject: Re: [2.4 PATCH] bugfix: ARP respond on all devices
> 
> 
> On Tue, 2003-08-19 at 13:53, David S. Miller wrote:
> 
> > BTW, this ARP source address algorithm we use comes from
> > ipv6, it would be instructive to go and see why they do
> > things the way they do.
> 
> Are you sure?  See below:
> 
> ========================================================================
> 
> RFC 2461              Neighbor Discovery for IPv6          December 1998
> 
> 
> 4.3.  Neighbor Solicitation Message Format
> 
>    Nodes send Neighbor Solicitations to request the link-layer address
>    of a target node while also providing their own link-layer address to
>    the target.  Neighbor Solicitations are multicast when the node needs
>    to resolve an address and unicast when the node seeks to verify the
>    reachability of a neighbor.
> 
>          0                   1                   2                   3
>          0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>         |     Type      |     Code      |          Checksum             |
>         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>         |                           Reserved                            |
>         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>         |                                                               |
>         +                                                               +
>         |                                                               |
>         +                       Target Address                          +
>         |                                                               |
>         +                                                               +
>         |                                                               |
>         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>         |   Options ...
>         +-+-+-+-+-+-+-+-+-+-+-+-
> 
>    IP Fields:
> 
>       Source Address
>                      Either an address assigned to the interface from
>                      which this message is sent or (if Duplicate Address
>                      Detection is in progress [ADDRCONF]) the
>                      unspecified address.
> 
>       Destination Address
>                      Either the solicited-node multicast address
>                      corresponding to the target address, or the target
>                      address.
> 
>       Hop Limit      255
> 
>       Authentication Header
>                      If a Security Association for the IP Authentication
>                      Header exists between the sender and the
>                      destination address, then the sender SHOULD include
>                      this header.
> 
> 
> 
> 
> 
> Narten, et. al.             Standards Track                    [Page 21]
> 
> ========================================================================
> 
> 
> Regards,
> 
> // Steve
> 
> 

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