[153790] in North American Network Operators' Group
Re: IPv6 /64 links (was Re: ipv6 book recommendations?)
daemon@ATHENA.MIT.EDU (Owen DeLong)
Tue Jun 12 21:15:31 2012
From: Owen DeLong <owen@delong.com>
In-Reply-To: <4FD7CFB3.70009@necom830.hpcl.titech.ac.jp>
Date: Tue, 12 Jun 2012 18:13:51 -0700
To: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Jun 12, 2012, at 4:24 PM, Masataka Ohta wrote:
> Tony Hain wrote:
>=20
>> Note the ~ ... And ARP requires media level broadcast, which ND does =
not.
>=20
> Any multicast capable link is broadcast capable.
BZZT! but thank you for playing.
Many NBMA topologies support multicast.
>=20
>> Not all media support broadcast.
>=20
> A fundamental misunderstanding of people designed IPv6 is that
> they believed ATM not broadcast capable but multicast capable.
>=20
This is, in fact, true.
Yes, you can synthesize ATM broadcast-like behavior, but it is not =
broadcast.
>>> As ND requires MLD and DAD, overhead in time when addresses are
>>> assigned is very large (several seconds or more if multicast is not =
very
>>> reliable), which is harmful especially for quicking moving mobile =
hosts.
>>=20
>> So leveraging broadcast is why just about every implementation does a
>> gratuitous ARP-and-wait multiple times,
>=20
> Not at all. IPv4 over something does not have to be ARP.
>=20
IPv4 over anything requires some form of L2 address resolution in any =
case
where L2 addresses must be discovered.
> IPv6 is broken eventually requiring all link use ND, even
> though ND was designed for stational hosts with only Ethernet,
> PPP and ATM (with a lot of misunderstanding) in mind.
>=20
Not really.
>> BS ... Broadcasts are dropped all the time,
>=20
> On Ethernet, broadcast is as reliable as unicast.
>=20
BS.
>> Just because you have never liked the design choices and tradeoffs =
made in
>> developing IPv6 doesn't make them wrong.
>=20
> It is the ignorance on the end to end principle which makes
> IPv6 wrong.
>=20
End-to-end is significantly more broken in IPv4 because of the need for =
NAT than it is in IPv6.
IIRC, you were the one promoting even more borked forms of NAT to try =
and compensate for this.
>> If there are constructive suggestions to make the
>> outcome better, take them to the IETF just like all the
>> constructive changes made to IPv4.
>=20
> IPv6 is a proof that IETF has lost the power to make
> the world better.
IPv6 is quite a bit better than IPv4 in many ways. It could be better =
still, but, it is definitely superior
to current IPv4 implementations and vastly superior to the IPv4 =
implementations that existed when
IPv6 was designed.
Owen
