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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!news.kei.com!sol.ctr.columbia.edu!startide.ctr.columbia.edu!wpaul From: wpaul@ctr.columbia.edu (Bill Paul) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: FreeBSD & Stevens TCP Vol II Book Date: 1 Jul 1995 20:41:11 GMT Organization: Columbia University Center for Telecommunications Research Lines: 78 Message-ID: <3t4bt7$pot@sol.ctr.columbia.edu> References: <ojkxlmg0sdbT073yn@sscp.lkg.dec.com> <3sn3lp$i9j@sol.ctr.columbia.edu> <W5Mzlmg0spzL073yn@hanson.iii.net> NNTP-Posting-Host: startide.ctr.columbia.edu X-Newsreader: TIN [version 1.2 PL2] Daring to challenge the will of the almighty Leviam00se, Michael C. Cambria (cambria@hanson.iii.net) had the courage to say: : In article <3sn3lp$i9j@sol.ctr.columbia.edu>, : wpaul@ctr.columbia.edu (Bill Paul) wrote: : > [snip] : > If you really want an exact copy of what's in the book, you can : > always obtain a copy of the 4.4BSD-Lite CD-ROM Companion from O'Reilly : > and Associates (costs about $40 US). This is basically a small book : > with a CD-ROM in the back containing the entire contents of the : > 4.4BSD-Lite distribution exactly as it was released by the CSRG before : > it bit the dust. I would actually suggest getting both FreeBSD 2.0.5 : > and the original 4.4BSD-Lite CD so you can study the original code : > *and* see it in action. (The 4.4BSD-Lite distribution is not a runnable : > OS -- it's just the unencumbered source without binaries). Walnut Creek : > should have 2.0.5 CDs available before too long (they might even : > have 4.4BSD-Lite CDs of their own for sale for all I know). In the : > meantime, you can always download 2.0.5 from ftp.cdrom.com. : Thanks Bill, : I already subscribe to FreeBSD from Walnut Creek. 2.05 should show : up in my mailbox shortly. The info from your which unconfused me was : "The 4.4BSD-Lite distribution is not a runnable OS -- it's just the : unencumbered source without binaries". If I understand you now, the : book "code walks" (specific) source code that doesn't actually run ( : 4.4BSD-Lite), while FreeBSD is an implementation base on that source : (and does run :-) : Thanks, : Mike Actually, the TCP/IP code on the 4.4BSD-Lite CD does run; the 4.4BSD-Lite release as a whole does not run, however. What I meant by 'not a runnable OS' is that you can't just take the contents of the 4.4BSD-Lite CD, type a 'make world' on it and expect it to work. The distribution is incomplete because 4.4BSD contains some code that's copyrighted by AT&T/USL/Novell/whoever-owns-SVR4-this-week, which prevents anybody who doesn't whole a System V source license from obtaining a copy. The 4.4BSD-Lite distribution contains all the code that isn't contaminated by the AT&T copyright. Consequently, it's missing a few pieces that prevent you from building a complete running system out of it. There are also no binaries on the CD, so even if you wanted to fill in the missing pieces yourself, you'd need to find a running system to do it on first. Note also that while there is 386 code in the 4.4BSD-Lite release, it doesn't include support for very much 386 hardware. FreeBSD, NetBSD and BSDI are derived directly from the 4.4BSD-Lite release, and as such they contain substantial chunks of code from it, including the TCP/IP code, which, luckily, was not subject to the AT&T copyright and was released completely intact. They do diverge from 4.4BSD-Lite in many places (FreeBSD, NetBSD and BSDI 2.0 have shared libraries, for example, which 4.4BSD-Lite doesn't) and include plenty of bug fixes and enhancements (some platform-specific, some not, like the merged VM/buffer cache in FreeBSD). Their TCP/IP implementations are virtually identical to what's in the 4.4BSD-Lite release, however. The differences are, as I said, some bug fixes and some enhancements. Even so, having the source code means you can see exactly what's been changed. The point I wanted to make was that while you are liable to find a few places where the TCP/IP code in FreeBSD diverges slightly from what's in the TCP/IP Illustrated books, there's no reason why you can't use FreeBSD as a working example of the books' discussions. The same applies to NetBSD and BSDI, but this is a FreeBSD newsgroup so we're not going to focus on them. :) -Bill -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~T~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Bill Paul (212) 854-6020 | System Manager Work: wpaul@ctr.columbia.edu | Center for Telecommunications Research Home: wpaul@skynet.ctr.columbia.edu | Columbia University, New York City ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The Møøse Illuminati: ignore it and be confused, or join it and be confusing! ~~~~~~ "Welcome to All Things BSDish! If it's not BSDish, it's crap!" ~~~~~~~