[139827] in North American Network Operators' Group
Re: Comcast's 6to4 Relays
daemon@ATHENA.MIT.EDU (Owen DeLong)
Wed Apr 20 16:46:50 2011
In-Reply-To: <4DAF3D8F.4020703@dougbarton.us>
From: Owen DeLong <owen@delong.com>
Date: Wed, 20 Apr 2011 16:41:51 -0400
To: Doug Barton <dougb@dougbarton.us>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Sent from my iPad
On Apr 20, 2011, at 4:09 PM, Doug Barton <dougb@dougbarton.us> wrote:
> On 04/20/2011 12:50, Owen DeLong wrote:
>> Turnning off the servers will not reduce the brokenness of 6to4, it will i=
ncrease it.
>=20
> Depends on your definitions of "increase" and "broken." If all the relays d=
isappeared tomorrow then the failure rate would be 100%, sure. But that woul=
d mean a single, (more or less) instant, deterministic failure that any mode=
rn OS ought to be able to handle intelligently; rather than the myriad of wa=
ys that 6to4 can half-succeed now. To me, that's a win.
>=20
>=20
Uh, no. It would, indeed, be a single deterministic failure. However, most O=
S are coded that if there isn't native, they'll try 6to4 if it's turned on. M=
any OS have it turned on by default.
As such, it would simply be a 100% failure, not one that was automatically d=
ealt with in a
rational or useful manner. It would require manual intervention on a large n=
umber of hosts.
To me, that's not a win. That's a loss.
The success rate for 6to4 today in most environments is close to 90%. There a=
re many environments in widespread use today (hotel networks and airports co=
me to mind) where IPv4 does not enjoy that level of success.
Owen
>=20
