IPv6 fc00::/7 ? Unique local addresses

Thu Oct 21 05:12:44 UTC 2010

On 10/20/10 9:44 PM, Adrian Chadd wrote:
> On Thu, Oct 21, 2010, Graham Beneke wrote:
> 
>> I've seen this too. Once again small providers who pretty quickly get 
>> caught out by collisions.
>>
>> The difference is that ULA could take years or even decades to catch 
>> someone out with a collision. By then we'll have a huge mess.

having merged datacenters with multiple overlapping v4 prefixes I'll
just observe that this is inevitable in v4, you can take steps that make
it less likely to impact you in v6.

> You assume that people simply select ULA prefixes randomly and don't
> start doing linear allocations from the beginning of the ULA range.

actually I assume they're going to just assign the whole botton half to
themselves like they do with 10/8 since using fc01::/8 is clearly more work.

If you do assign randomly the probability of someone deliberately
assigning the same /48 for use in their network seems pretty low, you're
a heck of a lot better off than with rfc 1918.

> 
> 
> 
> Adrian
> 
> 