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Re: Forwarding Packets With Link Local Destination Addresses

Philip Homburg <pch-ipv6-ietf-7@u-1.phicoh.com> Fri, 08 January 2021 12:05 UTC

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To: ipv6@ietf.org
Subject: Re: Forwarding Packets With Link Local Destination Addresses
From: Philip Homburg <pch-ipv6-ietf-7@u-1.phicoh.com>
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References: <DM6PR05MB6348A18046C5DDC7CF2AED76AEAF0@DM6PR05MB6348.namprd05.prod.outlook.com> <fc2600de-308a-7162-db12-d1d906302494@si6networks.com> <CAJE_bqfSkvpT0PfbGxPmJ450+_DWH_66O9h=pbRkn36mB27sBA@mail.gmail.com> <3F8BB900-B77E-473D-8DF2-02FEA3E2BA32@tzi.org> <2b6e4c6e-b4ab-a23f-72f8-d91442331622@moth.iki.fi>
In-reply-to: Your message of "Fri, 8 Jan 2021 13:13:46 +0200 ." <2b6e4c6e-b4ab-a23f-72f8-d91442331622@moth.iki.fi>
Date: Fri, 08 Jan 2021 13:05:11 +0100
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/RolEKiPSGRKNkFPsSvUx0GQh2ds>
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In your letter dated Fri, 8 Jan 2021 13:13:46 +0200 you wrote:
>I think the limitation (don't forward from higher scope to local on 
>routing header) should be kept and made extremely strong rule, 
>especially if the final address is a link local. No exceptions, ever.
>
>ND is already open to local attacks on local network, but this is 
>accepted. But, if random person on internet anywhere can inject ND 
>packets via routing header from outside the local network, it would be 
>very bad...

It should not affect ND. ND requires the hop limit to be 255 on the receiving
node.

Beyond that, if routing headers do not cross security boundries, then
I don't see a problem.

If routing headers do cross security boundaries, then you may have bigger
problems already.

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