IPv6 "bloat" history

Masataka Ohta mohta at necom830.hpcl.titech.ac.jp
Wed Mar 23 06:25:53 UTC 2022

William Allen Simpson wrote:

>   6) The Paul Francis (the originator of NAT) Polymorphic Internet Protocol
>      (PIP) had some overlapping features, so we also asked them to merge
>      with us (July 1993).  More complexity in the protocol header chaining.

With the merger, Paul Francis was saying he was unhappy
because PIP is dead. So the merger is not voluntary for
him and the added complexity is technically meaningless.

> IPv4 options were recognized as harmful.  SIPP used header chains instead.
> But the whole idea was to speed processing, eliminating hop-by-hop.
> Then the committees added back the hop by hop processing (type 0).
> Terrible!

Really? But, rfc1710 states:

    The SIPP option headers which are currently defined are:

      Hop-by-Hop Option          Special options which require hop by hop

> Admittedly, I was also skeptical of packet shredding (what we called
> ATM).

Packet shredding harmed router architecture, not protocols.
Many routers are shredding packets internally for no good

Instead, ATM-centric view that "all the world will be
covered by ATM and global IP could be used only over ATM"
harmed protocols including IPv6 a lot.

> Neighbor Discovery is/was agnostic to NBMA.  Putting all the old
> ARP and DHCP and other cruft into the IP-layer was my goal, so
> that it would be forever link agnostic.

To make "IP uber alles", link-dependent adaptation mechanisms
between IP and links are necessary. So, "ND uber alles" is a
wrong goal.

> Yes, we were also getting a push from Fermi Labs and CERN for very
> large numbers of nodes per link, rather than old ethernet maximum.

And the reason was that they want to use IPv4 and
DECNET without being annoyed by *dual* *stack* routers!

> That's the underlying design for Neighbor Discovery.  Less chatty.

Just wrong requirement.

Large Ethernet segments work poorly by itself. Worse, even
if some L3 might be causing additional damages, the
damages won't go away if IPv6 is added.

> Turns out it was the administration's IBM that
> had been clogging the campus.


						Masataka Ohta

More information about the NANOG mailing list