Using IPv6 with prefixes shorter than a /64 on a LAN

Jack Bates jbates at brightok.net
Fri Feb 4 17:25:44 CST 2011


On 2/4/2011 5:11 PM, Mark Andrews wrote:
> No, a /48 is equivalent to a single IP.
>
> You loose a little bit with small ISPs as their minimum is a /32
> and supports up to 64000 customers.  The bigger ISPs don't get to
> waste addresses space.  And if a small ISP is getting space from
> a big ISP it also needs to maintain good usage ratios.
>

Read the rest of what I said again. In the layout I used, a /32 is a 
/32. a /28 is a /28. Yet when you look at what is being assigned in IPv6 
and you look at what we assign in IPv4, it's pretty laughable.

It took years for me to get to a /16 of IPv4; where a /16 of IPv4 is 
small change for many large providers. In IPv6, a /16 is well out of my 
league and much larger than many large providers will ever need.

>> A /28 (medium ISP) is equiv to an IPv4 /28. A /24 (high
>> medium, large ISP) is equiv to an IPv4 /24. A /16 (a huge ISP) is equiv
>> to an IPv4 /16. Get the picture?
>>
>> So, I currently route a /16 worth of deaggregated IPv4 address space
>> (sorry, allocation policy fault, not mine). There is NEVER a time that I
>> will be allocated an IPv6 /16 from ARIN. Heck, the most I'll ever hope
>> for is the current proposal's nibble boundary which might get me to a
>> /24. I'll never talk to ARIN again after that.
>>
>>
>> Jack
>>




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