Issues encountered with assigning all ones IPv6 /64 address? (Was Re: Issues encountered with assigning .0 and .255 as usable addresses?)

Wed Oct 24 04:52:48 UTC 2012

On Tue, Oct 23, 2012 at 9:18 AM, Mike Jones <mike at mikejones.in> wrote:
> IPv4 addresses ending in .0 and .255 can't be used either because the
> top and bottom addresses of a subnet are unusable.
>
> Why would hetzner be making such assumptions about what is and is not
> a valid address on a remote network? if you have a route to it then it
> is a valid address that you should be able to exchange packets with,
> any assumptions beyond that are almost certainly going to be wrong
> somewhere.

As to why: I suspect they don't know either.  I wouldn't be surprised
if it was someone's misguided attempt years ago to stop smurf
amplification attacks, long since forgotten.  I'm not saying it's a
good idea (it's not), just why I suspect someone would do this.