Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)

Ted Lemon <> Sun, 14 February 2021 15:43 UTC

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From: Ted Lemon <>
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Date: Sun, 14 Feb 2021 10:43:03 -0500
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Cc: Brian E Carpenter <>, David Farmer <>, Fred Baker <>, IPv6 Operations <>, "" <>
To: Fernando Gont <>
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Subject: Re: [v6ops] Scope of Unique Local IPv6 Unicast Addresses (Fwd: New Version Notification for draft-gont-6man-ipv6-ula-scope-00.txt)
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On Feb 14, 2021, at 1:00 AM, Fernando Gont <> wrote:
> IMO, if the areas overlap, the scope ofa ULA1 and ULA2 are still the same. One scope is Area(ULA1): all the area where ULA1 addresses are unique and can be actively employed. The other one is Area(ULA2).
> The intersection of the two areas is part of the scope of each of the two ULAs (because in that region both ULA1 and ULA2 are unambiguous)

Since you still haven’t clearly articulated what you mean by “scope” with respect to ULA, it doesn’t make sense to say that one ULA has the same or a different scope than another. In any case, what you are describing here is precisely what the “label” entry in an RFC 6724 policy table does. Which is to say, you are not talking about scopes.

> This is not that different from the overlap of e.g. link-locals and GUAs on a local link….

Since the different treatment of GUAs and LLAs on a link is something that can be known by definition, and thus be handled by if-then-else statements rather than by table lookups, I would say that they are quite different.