AWS and IPv6

Sun Nov 28 23:50:30 UTC 2021

On Sun, Nov 28, 2021 at 02:10:40PM -0800, William Herrin wrote:
> On Sun, Nov 28, 2021 at 1:18 PM Karl Auer <kauer at biplane.com.au> wrote:
> > On Sun, 2021-11-28 at 12:53 -0800, Michael Thomas wrote:
> > > I was reading their howto yesterday and it seems they are only
> > > allocating a /64? Why?
> >
> > That's a /64 *per subnet*...
> >
> > But the size of a VPC's IPv6 CIDR block does seem to be fixed at /56.
> > Would have been nice to see /48 instead.
> 
> To what purpose? You can't alter the VPC routing of any of the IP
> addresses (v4 or v6) assigned to an AWS VPC.

Which is, fundamentally, half the problem with IPv6 in AWS.  I'd have much
preferred that they'd added the ability to do actually-useful IPv6 routing
rather than IPv6-only subnets, which strikes me as more of a toy than
something *actually* useful.

- Matt