Date: Thu, 19 Dec 2002 14:25:20 -0600 From: "Mark Johnston" <mjohnston@skyweb.ca> To: <freebsd-doc@freebsd.org> Subject: RE: FreeBSD Handbook Message-ID: <004201c2a79c$c0b1f4e0$690fa8c0@MJOHNSTON> In-Reply-To: <20021219195435.GA540@nosferatu.blackend.org>
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Marc Fonvielle wrote: > > 2) on page 53 in the section "Netmask" > > the Class C block should be 192.168.0.0-192.168.0.255 instead of > > 192.168.0.0-192.168.255.255 > > > > According to RFCs (rfc1918 for example), the Handbook is correct: > > The Internet Assigned Numbers Authority (IANA) has reserved the > following three blocks of the IP address space for private > internets: > > 10.0.0.0 - 10.255.255.255 (10/8 prefix) > 172.16.0.0 - 172.31.255.255 (172.16/12 prefix) > 192.168.0.0 - 192.168.255.255 (192.168/16 prefix) > > We will refer to the first block as "24-bit block", the second as > "20-bit block", and to the third as "16-bit" block. Note that (in > pre-CIDR notation) the first block is nothing but a single class A > network number, while the second block is a set of 16 contiguous > class B network numbers, and third block is a set of 256 contiguous > class C network numbers. The RFC1918 comment is accurate, but the paragraph is really explaining the Netmask field, so RFC1918 private networking is, IMO, unneeded complication. My suggestion would be to cut that and offer a more detailed explanation of how the netmask field is filled in; mentioning that it is often called a "subnet mask" would help new-to-Unix users. I would change the following text: The address block being used for this local area network is a Class C block (192.168.0.0 - 192.168.255.255). The default netmask is for a Class C network (255.255.255.0). to read something like: The subnet mask of the network. In this example, 255.255.255.0 has been automatically entered, since the IP address is a Class C address (i.e. in the range 192.0.0.0 - 223.255.255.255.) And Tom, isn't it "classless internet domain routing" - the wondrous upgrade that brought us /nn notation and non-8-bit boundaries? I'm going to check the book as soon as I've sent this mail.. :) Mark To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-doc" in the body of the message
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