Re: [v6ops] [EXTERNAL] Re: Improving ND security

Fernando Gont <> Mon, 03 August 2020 16:34 UTC

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To: "Templin (US), Fred L" <>, "Pascal Thubert (pthubert)" <>
Cc: v6ops list <>, 6man <>
References: <> <> <> <> <> <>
From: Fernando Gont <>
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Date: Mon, 3 Aug 2020 13:06:10 -0300
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Subject: Re: [v6ops] [EXTERNAL] Re: Improving ND security
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On 3/8/20 11:22, Templin (US), Fred L wrote:
> Here’s another think about SEND. RFC3971 SEND says that it works in 
> conjunction with Cryptographically Generated addresses (CGA) per RFC3972. But, CGAs are 
> cumbersome to work with as the source and destination addresses of IPv6 packets, 
> and SEND hints that it can be used without CGA but does not tell how to do so.

Of the top of my head, CGAs are a core part of send.

> But then, RFC4380 offers a “poor-man’s” alternative to SEND/CGA. It 
> places a message authentication code in the encapsulation headers of IPv6 ND messages so 
> that the messages can pass a rudimentary authentication check.

You mean the Teredo spec? If so, I don't think it includes any sort of 
poor-man's SEND-CGA.

> So someone with 
> security experience please help me out here – is RFC4380 authentication an acceptably
> secure  replacement for SEND/CGA that might be easier to work with and less
> cumbersome?

Nope. Tee point of CGAs is that they allow you to prove address 
ownership. There's nothing in RFC4380 that provides the same or similar 

Fernando Gont
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