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From: art@opal.acc.com (Art Berggreen)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Unused portion of first octet?
Message-ID: <1991May20.165505.14235@salt.acc.com>
Date: 20 May 91 16:55:05 GMT
References: <1991May20.160942.24296@homecare.COM>
Sender: news@salt.acc.com
Reply-To: art@opalacc.com (Art Berggreen)
Organization: Advanced Computer Communications, Santa Barbara, California
Lines: 16

In article <1991May20.160942.24296@homecare.COM> jessea@homecare.COM (Jesse W. Asher) writes:
>Correct me if I'm wrong, but Class A-C networks depend on the number of
>the first octet in the address.  Class A is 1-127, Class B is 128-191,
>and Class C is 192-223.  What happens to 224-254?  What are these being
>used for, or are they being used for anything?  Just a curious mind
>wanting to know.

Its not actually the first octet, bit the first bits, as follows:

	0XXXXXXX.XXXXXXXX.XXXXXXXX.XXXXXXXX	Class A
	10XXXXXX.XXXXXXXX.XXXXXXXX.XXXXXXXX	Class B
	110XXXXX.XXXXXXXX.XXXXXXXX.XXXXXXXX	Class C
	1110XXXX.XXXXXXXX.XXXXXXXX.XXXXXXXX	Class D (Multicast)
	1111XXXX.XXXXXXXX.XXXXXXXX.XXXXXXXX	Reserved

Art