nanog mailing list archives

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


From: Jack Bates <jbates () brightok net>
Date: Fri, 04 Feb 2011 17:25:44 -0600

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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