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[IPv6]Re: [v6ops] New draft: "The IPv6 Loopback Address Prefix"

Geoff Huston <gih902@gmail.com> Tue, 25 November 2025 19:20 UTC

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From: Geoff Huston <gih902@gmail.com>
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Date: Wed, 26 Nov 2025 06:20:07 +1100
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To: Jeremy Duncan <jduncan@tachyondynamics.com>
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CC: Warren Kumari <warren@kumari.net>, IPv6 <ipv6@ietf.org>, IPv6 Operations <v6ops@ietf.org>
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Subject: [IPv6]Re: [v6ops] New draft: "The IPv6 Loopback Address Prefix"
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Hi Jeremy

>  
> So this one: 0:0:0:0:0:0:0:0 – 0:0:0:0:0:0:FFFF:FFFF
>  
> right?
>  


You are of course correct - I was counting the number of bit to the right, where I should been counting the bits to the left

:-)

its a 96 - will be fixed in the next rev Thanks for spotting this!

Geoff





> On 26 Nov 2025, at 4:55 am, Jeremy Duncan <jduncan@tachyondynamics.com> wrote:
> 
> Hi Warren/Geoff-
>  
>    ((Geoff: I have gone for a simple prefix that sits below the
>    IPv4-mapped address block of 0:0:0:0:0:FFFF::/32 - the complication
>    is that the prefix then includes the "unspecified address" as well.))
>  
> Regarding the IPv4-mapped address prefix, just to clarify, it’s a /96 not a /32 right?
>  
> The recommendation is saying that the loopback prefix will be a /96 not a /32 right?
>  
> So this one: 0:0:0:0:0:0:0:0 – 0:0:0:0:0:0:FFFF:FFFF
>  
> right?
>  
> Or are you saying 0:0:0:0:0:0:0:0 – 0:0:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF
>  
> -Jeremy
>

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