Issues encountered with assigning .0 and .255 as usable addresses?

Tue Oct 23 20:00:53 UTC 2012

* Job Snijders

> In the post-classfull routing world .0 and .255 should be normal IP
> addresses. CIDR was only recently defined (somewhere in 1993) so I
> understand it might take companies some time to adjust to this novel
> situation. Ok, enough snarkyness!
> 
> Quite recently a participant of the NLNOG RING had a problem related
> to an .255 IP address. You can read more about it here:
> https://ring.nlnog.net/news/2012/10/ring-success-the-ipv4-255-problem/

AIUI, that particular problem couldn't be blamed on lack of CIDR support
either, as 91.218.150.255 is (was) a class A address. It would have had
to be 91.255.255.255 or 91.0.0.0 for it to be special in the classful
pre-CIDR world.

That said, it's rather common for people to believe that a /24 anywhere
in the IPv4 address space is a «class C» so I'm not really surprised.

-- 
Tore Anderson
Redpill Linpro AS - http://www.redpill-linpro.com/