nanog mailing list archives

Re: Did Internap lose all clue?


From: Matt Buford <matt () overloaded net>
Date: Sat, 22 Oct 2011 00:13:49 -0500

On Thu, Oct 20, 2011 at 8:08 PM, <Valdis.Kletnieks () vt edu> wrote:

Yes, it's possibly foolish to allocate x.y.z.0 or .255.


But saying that that x.y.z.0 is *not* *capable* of representing an
interface is
demonstrating a dangerous lack of knowledge.  There's several totally legal
.0
and .255 addresses in each /22 subnet, and yes people *do* use /22 subnets.
Unfortunately, we're still stuck with  "Don't use .0 or .255, because there
are
*still* people out there who don't understand CIDR and will hassle you
about it"...


A decade ago, I recall allocating a /23 to a dialup pool and getting calls
from customers who landed on .0 and .255 because they were unable to reach
random sites.  It should be legal, but doesn't always work.  I assumed this
was still the case.

Several months ago, I fired up a permanent aws ec2 instance with a static
IP.  To my surprise, they allocated me a .0 address.  I haven't noticed any
issues with it at all.  But I figure if Amazon is using .0 as a normal part
of their deployments, their scale is so high that if it didn't work reliably
you'd think they would have noticed by now.  I don't know if they also use
.255.


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