IPv6 RA vs DHCPv6 - The chosen one?

Masataka Ohta mohta at necom830.hpcl.titech.ac.jp
Wed Dec 28 11:33:23 UTC 2011

Valdis.Kletnieks at vt.edu wrote:

>> IPv6 does not work well in many environments.
> Feel free to try to deprecate *everything* that doesn't work well in many
> environments.

Why not?

> Heck, SMTP doesn't work well in many environments (it's done in
> cleartext unless you deploy STARTTLS, it's subject to spamming, etc etc)

Red herring.

I thought all of us on some mailing list recognize SMTP working

But, if you insist you don't, feel free not to use it, which means
you leave most, if not all, mailing lists including NANOG ones.

> It's one thing to deprecate something that's obviously a complete failure or
> has reached historic status - but RA isn't either of those *yet*.

That is not a valid counter argument against a proposal to
make RA deprecated, that is, make RA reach historic status.

>> In this case, the following statement in RFC1883:
>>>    If the minimum time for rebooting the node is known (often more than
>>>    6 seconds),
>> is the wrong assumption which made RA annoying.
> Oddly enough, a lot of us are running on networks where assuming this about end
> user gear is perfectly reasonable.

That is because, as I wrote already in the previous mail,

>	Network configuration was mostly stationary

For example, IPv6 might work well, if most of your end users
are not moving rapidly between small mobile cells.

However, assuming you change the cells every 100m in average
and you are moving at 100km/h, you must change the cells every
3.6 seconds in average, which means you must be able to change
the cells frequently, which means each cell change take a lot
less than 3.6 seconds.

> We haven't seen many consumer-grade
> Windows, Macs, or Linux boxes that are able to reboot in much under 6 seconds.

IPv6 is wrongly architected, not because it assumes nodes are
able to reboot in much under 6 seconds, but because it assumes
new configurations necessary only at boot time.

> Yes, I know you can do it with careful tuning and throwing SSDs and other
> hardware at it - doesn't mean it's common.

Obviously, the IPv6 committee and you are assuming computers
of immobile main frame computers or, at least, immobile

However, in the real world, commonly available mobile phones
are IP capable computers which wake up from dormant state
within a second and needs handover often within a second.

						Masataka Ohta

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