Re: Bad handling of .0 and .255 addresses

From: Michael H. Warfield (mhw@wittsend.com)
Date: Tue May 16 2000 - 12:03:12 EST


On Tue, May 16, 2000 at 08:49:20AM -0900, Christopher E. Brown wrote:
> On Tue, 16 May 2000, Ed Carp wrote:
> > Did you deliberately overlook the point? It's not the routers that were my
> > point, it was the hosts that respond to such broadcasts.

> There is not a point here. The addresses *would* have been a
> network or broadcast address under old classful systems, and they
> might be now, or they might not be.

        Not for a Class B.

        I have a Class B. Address 130.205.8.255 is a perfectly legitimate
host address under both the Class system and the CIDR system unless
I apply a /24 mask or finer. What you say is very true for a Class C
under the Class system or for a /24 under CIDR.

        I would expect a host on 130.205.16.0/20 with an address of
130.205.24.255 to behave perfectly well with that as a unicast address.
I would not expect any other host on the 130.205.16.0/20 network to respond
to that address. And the host address obviously does end in .255.

> *IF* you have a network, that *uses* these addresses and
> network and broadcast, then your *last* hop router should
> respond/block this traffic, if you network *DOES NOT* use them this
> way then they are valid addresses.

> ---
> As folks might have suspected, not much survives except roaches,
> and they don't carry large enough packets fast enough...
> --About the Internet and nuclear war.

        Mike

-- 
 Michael H. Warfield    |  (770) 985-6132   |  mhw@WittsEnd.com
  (The Mad Wizard)      |  (770) 331-2437   |  http://www.wittsend.com/mhw/
  NIC whois:  MHW9      |  An optimist believes we live in the best of all
 PGP Key: 0xDF1DD471    |  possible worlds.  A pessimist is sure of it!

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