Dual stack IPv6 for IPv4 depletion

Thu Jul 9 21:58:56 UTC 2015

>> Huh, since when does ANY application care about what size address 
>> allocation you have?  A V6 address is a 128 bit address period.  Any 
>> IPv6 aware application will handle addresses as a 128 bit variable.

>The DHCPv6-PD server application on your router(s) might care.

Do you know of a DHCPv6-PD or router code that will accept a /56 and not a /48?  If you do, I suggest you open a bug with that vendor and tell them that either is a legal prefix length.

>> Does any application running on IPv4 care if you have a /28 or a /29?  
>> In fact the application should not even be aware of what the net mask 
>> is because that is an OS function to handle the IP stack.  This 
>> argument makes no sense at all since every application will be able to 
>> handle any allocation size since it is not even aware what that is.  
>> Any IPv6 compatible OS will not care either because they would be able 
>> to handle any number of masked bits.  No app developer has ever been tied into the size of a subnet since CIDR was invented.

>For an application that doesn't do anything with IP addresses (allocating, etc.), it shouldn't matter, but that does not mean that there aren't applications for which it does.
>
>-Randy

One should demand that application that care about allocation size, routing, etc would not be "IPv6 compatible" if they cannot handle all mask length legal under the protocol specification.  The reason there is a v6 standard is to define what is allowable or not, that is what a protocol IS.  We do not need to decide by committee to limit those options.

Steven Naslund
Chicago IL 