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

Philip Homburg <> Tue, 16 February 2021 16:20 UTC

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Date: Tue, 16 Feb 2021 17:20:30 +0100
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Subject: Re: [v6ops] [EXTERNAL] Re: 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 16, 2021, at 11:01 AM, Gert Doering <[1]>
>    wrote:
>      I cannot comment this in any way that is not full of negativism
>      about the achievements of IETF work in the area of SoHo
>      multihoming.  Sorry.
>    Actually, RFC 8028 seems to address this problem correctly at
>    least for the single-link model:
>    Default Router Selection ([2]Section 6.3.6 of [RFC4861]) is
>    extended as follows: A host SHOULD select default routers for
>    each prefix it is assigned an address in.  Routers that have
>    advertised the prefix in their Router Advertisement message
>    SHOULD be preferred over routers that do not advertise the
>    prefix, regardless of Default Router Preference.  Note that this
>    document does not change the way in which default router
>    preferences are communicated [[3]RFC4191].

We have a lot of protocol already. I have played extensively with moving
hosts from one upstream to another or what you can do with flash renumbering.

One big problem is that if you add it all up it becomes very complex. 
Certainly for people with an IPv4 background it is hard to figure out how
things should work. So the obvious way forward for them is to insert some
kind of NAT.

>From an application point of view, if you have to support IPv4 and NAT, is
it hard to support NAT for IPv6 as well?