Subject: Erik Kline's Abstain on draft-ietf-bfd-vxlan-15: (with COMMENT)

From: Erik Kline via Datatracker <[email-masked]>
Date: Sat, 03 Oct 2020 16:08:20 -0700

Erik Kline has entered the following ballot position for
draft-ietf-bfd-vxlan-15: Abstain

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COMMENT:
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doc{draft-ietf-bfd-vxlan-15}
ballot{Abstain}

[[ comments ]]

I was tempted to ballot Discuss, but I'm not sure about re-opening old
discussions into which I've no insight (it all happened before my tenure).

[ sections 3,5 ]

* I agree with Eric Vyncke's concerns about the use of ::ffff:127.0.0.0/104
  space.  This is not especially well-motivated, nor do I think the use of
  127.0.0.0/8 is particularly well-motivated.

  In IPv6, 2001::/23 is reserved for IETF protocol assignments and in my
  opinion this is an example of where that should be used.

  There is also still plenty of space to carve out from 192.0.0.0/24 for
  internal tunnel uses like this.

  Alternatively, a better approach might be for each VTEP to allocate their
  own IPv4 and/or IPv6 link-local addresses and uses these addresses for
  whatever traffic is to be sent within the data plane.  If the VTEPs use
  inner Ethernet headers for this traffic, then this would seem to make
  more sense to me.

[ section 9 ]

* It's not clear that the security of a prohibition on routers is sufficiently
  motivating securit when the packet is logically "switched" because it's on
  the same (effectively) VLAN.  The same router forwarding prohibition applies
  to link-local IP addresses and these could be used instead.

* What prevents a machine like VM1-1 from crafting a packet with the magic
  destination MAC and src & dst IPs from the magic range?  Should there be
  text about not forwarding any packets from VMs toward the magic dst MAC?