what about the users re: NAT444 or ?

Owen DeLong owen at delong.com
Wed Sep 14 07:29:40 CDT 2011


On Sep 13, 2011, at 10:18 PM, Dan Wing wrote:

>> One can do that with or without NAT. This claim that one cannot
>> keep a network running without a service provider connected if you
>> don't run NAT is a myth of dubious origin.
> 
> If the hosts are running DHCP, and the ISP is running the DHCP
> server?  I guess they will fall back (after a while) to link-local
> and continue on their merry way.
> 

That's some pretty big IFs. Even if I were using DHCP to get the prefix
from my service provider via DHCP-PD, I'd back-stop that with some
form of local DHCP server and deal with the need for manual intervention
when the provider renumbered me.

In my experience, getting renumbered is a rare enough experience that
I don't pay Comcast $60/year for a static address.

Owen

>>> can accomplish this pretty easily, because the IPv4 addresses in
>>> the home can be any IPv4 address whatsoever -- which allows the
>>> in-home CPE ("B4", in Dual Stack-Lite parlance) to assign any address
>>> it wants with its built-in DHCP server.)
>>> 
>> 
>> There are other ways to accomplish this as well.
> 
> -d
> 
>>> -d
>>> 
>>>> and less technically but relevant I think is to ask about cost? who
>>>> pays?
>> 
>> In some cases, ISPs will provide new CPE to their end users. In other
>> cases,
>> end-users will be expected to pay to upgrade their own.
>> 
>> Owen
>> 
>>>> 
>>>> 
>>>> Christian
>>>> 
>>>> On 8 Sep 2011, at 15:02, Cameron Byrne wrote:
>>>> 
>>>>> On Sep 8, 2011 1:47 AM, "Leigh Porter"
>> <leigh.porter at ukbroadband.com>
>>>> wrote:
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>>> -----Original Message-----
>>>>>>> From: Owen DeLong [mailto:owen at delong.com]
>>>>>>> Sent: 08 September 2011 01:22
>>>>>>> To: Leigh Porter
>>>>>>> Cc: Seth Mos; NANOG
>>>>>>> Subject: Re: NAT444 or ?
>>>>>>> 
>>>>>>>> Considering that offices, schools etc regularly have far more
>> than
>>>> 10
>>>>>>> users per IP, I think this limit is a little low. I've happily
>> had
>>>>>>> around 300 per public IP address on a large WiFi network, granted
>>>> these
>>>>>>> are all different kinds of users, it is just something that
>>>> operational
>>>>>>> experience will have to demonstrate.
>>>>>>>> 
>>>>>>> Yes, but, you are counting individual users whereas at the NAT444
>>>>>>> level, what's really being counted is end-customer sites not
>>>> individual
>>>>>>> users, so the term
>>>>>>> "users" is a bit misleading in the context. A given end-customer
>>>> site
>>>>>>> may be from 1 to 50 or more individual users.
>>>>>> 
>>>>>> Indeed, my users are using LTE dongles mostly so I expect they
>> will
>>>> be
>>>>> single users. At the moment on the WiMAX network I see around 35
>>>> sessions
>>>>> from a WiMAX modem on average rising to about 50 at peak times.
>> These
>>>> are a
>>>>> combination of individual users and "home modems".
>>>>>> 
>>>>>> We had some older modems that had integrated NAT that was broken
>> and
>>>>> locked up the modem at 200 sessions. Then some old base station
>>>> software
>>>>> died at about 10K sessions. So we monitor these things now..
>>>>>> 
>>>>>> 
>>>>>>> 
>>>>>>>> I would love to avoid NAT444, I do not see a viable way around
>> it
>>>> at
>>>>>>> the moment. Unless the Department of Work and Pensions release
>>>> their /8
>>>>>>> that is ;-)
>>>>>>>> 
>>>>>>> 
>>>>>>> The best mitigation really is to get IPv6 deployed as rapidly and
>>>>>>> widely as possible. The more stuff can go native IPv6, the less
>>>> depends
>>>>>>> on fragile NAT444.
>>>>>> 
>>>>>> Absolutely. Even things like google maps, if that can be dumped on
>>>> v6,
>>>>> it'll save a load of sessions from people. The sooner services such
>>>> as
>>>>> Microsoft Update turn on v6 the better as well. I would also like
>> the
>>>> CDNs
>>>>> to be able to deliver content in v6 (even if the main page is v4)
>>>> which
>>>>> again will reduce the traffic that has to traverse any NAT.
>>>>>> 
>>>>>> Soon, I think content providers (and providers of other services
>> on
>>>> the
>>>>> 'net) will roll v6 because of the performance increase as v6 will
>> not
>>>> have
>>>>> to traverse all this NAT and be subject to session limits, timeouts
>>>> and
>>>>> such.
>>>>>> 
>>>>> 
>>>>> What do you mean by performance increase? If performance equals
>>>> latency, v4
>>>>> will win for a long while still. Cgn does not add measurable
>> latency.
>>>>> 
>>>>> Cb
>>>>>> --
>>>>>> Leigh
>>>>>> 
>>>>>> 
>>>>>> 
>>>> 
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>> ______________________________________________________________________
>>>>>> 
>>> 
>>> 




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