[ale] IPv6 Subnetting

Michael B. Trausch mike at trausch.us
Tue Feb 15 12:56:37 EST 2011


On Tue, 2011-02-15 at 12:14 -0500, Michael H. Warfield wrote:
> Don't go there if you can avoid it.  We want to avoid IPv4 mind think
> here.
> 
> If you need more than one subnet, you're suppose to get a larger
> allocation and the ISP should make one available.
> 
> Per the standards...
> 
> If you need 1 subnet you get a /64.  If you need more than one subnet,
> you should get a /48 but some ISPs such as freenet6 may break that
> down further and hand you a /56 which is still 256 subnets.  Yes, most
> ISPs should be handing you a /64 as a default.  That is per the
> standard if that's all you need and that will be the case with most
> residential customers.  If you need more, they should allocate you
> more or they are in violation of the standards. 

Oh, indeed.

That said, I can imagine that there will be lots of ISPs that won't even
know how to handle such a request.  Hell, there are now, for IPv4, and
we've been running that for decades.

I plan on testing a setup like what I described, just for the sake of
verifying that it all works.  In theory, it should.  Of course, it
screws up a lot of the automatic help and thus convenience... and it
might even make things break that expect to never see something greater
than a /64.  There are a number of IPv6 calculators out there on the net
that simply absolutely insist that it's not possible to have a network
with more than 64-bits in the prefix.  I would not be surprised if there
are such assumptions in application software or network stacks.

	--- Mike
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: This is a digitally signed message part
Url : http://mail.ale.org/pipermail/ale/attachments/20110215/54806a80/attachment.bin 


More information about the Ale mailing list