Failover IPv6 with multiple PA prefixes (Was: IPv6 fc00::/7 - Unique local addresses)

Sun Oct 31 17:26:46 UTC 2010

On 10/31/2010 9:31 AM, Owen DeLong wrote:
>
> Or better yet, if Woody had gone straight to PI, he wouldn't have this problem,
> either.
>
And he can justify PI when he first deploys IPv6 with a single provider 
under which policy? (Assume he is in the ARIN region and that his IPv4 
space is currently provider-assigned from a couple of different 
providers and he's using NAT to do his IPv4 failover management)

1. Quite possibly does not qualify for an IPv4 assigned under the 
current IPv4 policy (certainly not in a few more months, when *nobody* 
will qualify except for some transition-space requests)

2. Definitely can't show efficient utilization of all direct IPv4 
assignments, as he has none.

3. He's not a community network.

So he can't go "straight to PI". He either needs to go PA with the first 
provider, then through renumbering pain (which he knows all too well 
about from IPv4, and none of the problems like "change the address of 
the intranet wiki server in the internal DNS servers" change with IPv6), 
or use something internal like ULA for things he doesn't want to renumber.

>> If a site is numbering their internal IPv4 stuff to avoid having to renumber
>> on a provider change, then why would they number their IPv6 stuff from
>> provider space rather than ULA space?
>>
> Which gains what vs. PI?
Nothing, but PI isn't available to him. See above.
>> And remember - (a) IPv6 allows machine to easily support multiple addresses and
>> (b) if you have  a provider address and a ULA, changing providers only means
>> renumbering a *partial* renumber of the hosts that require external visibility
>> - your internal hosts can continue talking to each other on a ULA as if nothing
>> happened.
>>
> If you have PI space, changing providers can be even easier and you can leave
> multiple providers running in parallel.

That's a big IF, given the above. He doesn't qualify for PI space, 
thanks to ARIN policies set by people who want routing tables to stay as 
small as possible, so PI space to be as difficult as possible to obtain 
for people like him.

Matthew Kaufman