[dhcwg] how do routers with DHCPv6 relays learn when they can delete delegated prefixes

Michael Richardson <mcr+ietf@sandelman.ca> Thu, 15 October 2020 00:14 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: dhcwg <dhcwg@ietf.org>, IPv6 List <ipv6@ietf.org>
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Date: Wed, 14 Oct 2020 20:14:51 -0400
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Subject: [dhcwg] how do routers with DHCPv6 relays learn when they can delete delegated prefixes
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Bob Hinden <bob.hinden@gmail.com> wrote:
    >> On Oct 14, 2020, at 8:55 AM, Templin (US), Fred L <Fred.L.Templin@boeing.com> wrote:
    >>
    >> Philip,
    >>
    >>> 2) Multiple downstream routers on a single link where the downstream routers
    >>> also do not speak a routing protocol. I doubt that we need to support
    >>> this configuration.
    >>
    >> That depends on how you define "routing protocol". DHCPv6 PD driven
    >> by IPv6 ND router discovery would in spirit constitute a routing protocol.

    > DHCPv6 PD / IPv6 ND is not a routing protocol.  Routing protocols are
    > things like OSPF, BGP, Babel, ISIS, etc.

I agree.
DHCPv6-PD needs to interact with routing protocols.  We never said how this works.

In the absense of having standardized that, we have hacks that occur in
DHCPv6 Relays that attempt to treat DHCPv6 traffic as if it was a routing
protocol, when it's not.

That's where the origin of this architectureal failure is.
DHCPv6-PD is a critical part of the IPv6 architecture that allows to say, "No NAT66"
if it doesn't work, then the industry will solve it with NAT66.


{I've left v6ops off. Put it back in the CC if you like}

--
Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide