Using /126 for IPv6 router links

Joe Maimon jmaimon at
Tue Jan 26 14:54:59 UTC 2010

Owen DeLong wrote:

> No, they're not impossible to exhaust, just pretty difficult.
> However, If we see exhaustion coming too soon in this /3, we can always apply a more conservative
> numbering policy to the next /3. (And still have 5 /3s left to innovate and try other alternatives).
> Owen


We have had this conversation before, but I just wanted to put my two 
cents out there again.

I dont view /3 as a safety valve. I view it as a possible escape pod 
from a sinking ship.

If it needs to be utilized, the entire world has been dealt a large 
disservice - something great pains should be taken to avoid. I doubt it 
would be an "oops, ime sorry, no harm done".

It should not be a factor to add risk into allocation design.

Furthermore, any allocation holder trying the same trick of reserving a 
greater than half of their block for the safety valve in their numbering 
scheme might quickly discover that their block is a bit more cramped 
than they thought it would be.

For me, the entire debate boils down to this question.

What should the objective be, decades or centuries?


More information about the NANOG mailing list