Ars Technica on IPv4 exhaustion

Karl Auer kauer at
Thu Jun 19 23:23:27 UTC 2014

On Thu, 2014-06-19 at 15:55 -0700, Owen DeLong wrote:
> With a small amount of conceptual knowledge, the differences between
> IPv4 and IPv6 become very very small.

True story: At a previous employer, a local admin had pushed his network
over 250-odd PCs and wanted more addresses. So we extended his /24 to
a /23. All coordinated - it was after work on a Friday, he was going to
renumber everything. This was before DHCP had been fully deployed, and
he had a lot of statically configured machines.

He rang the next day in a bit of a flap, because "the new addresses
don't work!" We pressed for more info. "They all work fine up to 254",
he said, "but from 255 up they aren't even accepted by the configuration
untility! I've tried all the way up to 300!"

He wasn't dumb - far from it - he'd just never been outside a /24
before, so had never needed to understand what the numbers *meant*.

Regards, K.

Karl Auer (kauer at

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