North American Network Operators Group

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Re: APNIC returning 223/8 to IANA

  • From: Stephen J. Wilcox
  • Date: Sun Mar 23 20:18:06 2003

On Sun, 23 Mar 2003 [email protected] wrote:
> > On Fri, Mar 21, 2003 at 12:11:47PM -0500, [email protected] wrote:
> > 
> > > Would you agree, as I've suggested, that there is no inherent
> > > technical limitation to using 223.255.255.0/24?
> > 
> > FWIW, I still see 'classful behavior' with WindowsXP (all recent
> > service packs and such like) and also Solaris 2.7 (not sure about
> > later releases, I'm guessing it's still there though).
> > 
> > My point here is that many years after CIDR we still get weird
> > anomalies in IP stacks --- so I wouldn't bet on anything being safe
> > unless well tested.
> 
> I don't doubt that there are OS's with bugs. However, my assertion is
> that 223.255.255.0/24 would continue to work under even Pre-CIDR gear.
> Therefore, even if an OS exhibited classful behaviour, that would
> be unrelated to the usefulness of 223.255.255.0/24.
> 
> Are you saying that Class-based routers can not use 223.255.255.0/24?

Thats a valid network, should be fine.

> Aside from real design errors or unintended Features, 223.255.255.0/24
> (and 192.0.0.0/24, 128.0.0.0/16, and 191.255.0.0/16) should be able to

But 191.255.255.255/24 or 191.255.0.0/24 are not usable for that Class B 
network. (Also 128.0.0.0/24 , 128.0.255.255/24 for that one)

Which is where I am confused... if routing is classless, and RIR allocation is 
also classless (That is I can get 200.10.20.0/24 rather than 200.10.20.0 Class C 
or 200.10.0.0/16 rather than 200.10.(0-255).0/24's) why are we bothered about 
this at all. 

In fact, if you dont want to risk upsetting possible classful routers then you 
shouldnt assign any classless networks.. 

And on the subject of "broken" classful routers out there surely this is only a 
problem if the awkward network is assigned to that router as an external route 
should still be fine (this is an issue to do with subnet calculation within a 
network - right?)

So just un-reserve all these blocks and hand them out, if anyone complains that 
they are running classful routers and it wont work give them another block or 
tell them to upgrade! 


Long thread this.. cant see why!

Steve

> be assigned, should the IANA no longer need to maintain the reservations.
> That being that they are/were reserved to be assigned to some purpose,
> and not because they couldn't ever be used.
> 
> 
>