[Cerowrt-users] IPv6 router advertisements on custom interfaces

Dave Taht dave.taht at gmail.com
Mon Dec 10 09:51:44 EST 2012


On Mon, Dec 10, 2012 at 3:42 PM, Steven Barth <cyrus at openwrt.org> wrote:
> For OpenWrt, npt66 won't be the default method - instead the default should
> be to split up the WAN prefix to distribute to downstream interfaces and
> fallback to relaying if there are no prefixes.
>
> I personally think npt66 would not make much sense outside of multi-uplink
> situations at least for plain OpenWrt, I cannot speak for CeroWrt.

My concern is explained by example.

I'm a fire department in the path of hurricane sandy. Power goes out.
I have a 7 day public ipv6 lease from a provider like comcast. A team
of volunteers get on bicycles connected to generators to keep the
servers and radios up and connected to the outside world.

Power stays out for 3 weeks. The public lease expires in 1 week.

Power flickers on, briefly. 40,000 users all apply for a new ipv6
lease at the same time. The lease changes. Power goes out.... the
network tries to renumber but has only partial connectivity... power
comes back on... lease changes again... the box in the corner that
controls the satellite uplink doesn't get a message and loses
connectivity entirely... people die.

I am making no long term design decisions vs a vs npt66 at this
point... but I have a strong bias towards only using ipv6 addresses on
an internal net that are as constant as the universe, and as constant
as ipv4 nat. Period.

Lest you think this is not a viable scenario, (although I would hope
hurricane sandy is high in many minds)....

power in nicaragua flickers 6 times a day....

>
>
>
> On 10.12.2012 15:23, Michael Richardson wrote:
>>>>>>>
>>>>>>> "Dave" == Dave Taht <dave.taht at gmail.com> writes:
>>
>>      Dave> Also planned is to (once the 3.7 kernel lands) make npt66 the
>> default
>>      Dave> (for most users). So in a couple weeks, all the underlying ipv6
>>      Dave> infrastructure in openwrt and cerowrt is going to change.
>>
>> Pardon?
>>
>



-- 
Dave Täht

Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.html



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