I'd go with socket basics.

Post #225,444 by jake123 9/19/05 10:52:57 AM Reply	I'd go with socket basics. It's not that difficult conceptually, and will make How It All Works much clearer than any other thing you can do. After all, once you get the connection made and can pass text back and forth, creating a service is just all about how it's processed at each end. To my mind, I'd start with the socket basics, keep it quite basic, and point them at further info if they wish to follow up on their own. After seeing how sockets work, showing them the kinds of things you can do with nmap etc will be much much clearer to them. Start down near the root, and move the course further up the tree as it progresses. --\n-------------------------------------------------------------------\n* Jack Troughton jake at consultron.ca \n [link\|http://consultron.ca\|http://consultron.ca] [link\|irc://irc.ecomstation.ca\|irc://irc.ecomstation.ca] \n Kingston Ontario Canada [link\|news://news.consultron.ca\|news://news.consultron.ca] *\n-------------------------------------------------------------------
Post #225,451 by admin 9/19/05 11:23:15 AM Reply	Re: I'd go with socket basics. Server: #!/usr/bin/python\n\nimport sys, socket\n\nif (len(sys.argv) < 2):\n sys.exit('Must supply port!\\n')\n\nport = sys.argv[1]\nhost = socket.gethostbyname(socket.gethostname())\n\nprint '%s:%s Listening:\\n' % (host, port)\n\nsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)\ntry:\n sock.bind((host, int(port)))\n sock.listen(1)\n\n conn, addr = sock.accept()\n print 'Connection from: ' + str(addr)\n\n str = conn.recv(1024)\n print 'Echoing "%s"' % (str)\n conn.send(str)\n\n conn.close()\n\nexcept socket.error, (errno, errstr):\n conn.close()\n sys.exit("Error: %s!" % (errstr)) Client: #!/usr/bin/python\n\nimport sys, socket\n\nif (len(sys.argv) < 4):\n sys.exit('Must supply host, port, and text string to send!\\n')\n\n(host, port, string) = sys.argv[1:]\n\nprint '%s:%s Sending: %s\\n' % (host, port, string)\n\nsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)\ntry:\n sock.connect((host, int(port)))\n sock.sendall('%s\\n' % (string))\n recv = ''\n while 1:\n str = sock.recv(1024)\n if not str: break\n recv += str\n\nexcept socket.error, (errno, errstr):\n sock.close()\n sys.exit("Error: %s!" % (errstr))\n\nprint "Received:\\n" + recv Regards, -scott anderson "Welcome to Rivendell, Mr. Anderson..."
Post #225,458 by jake123 9/19/05 12:50:17 PM Reply	Didn't say it would take very long :) Of course, for the students that DON'T know programming, learning that will take quite a bit longer; OTOH, once they DO grok it, they will be much better positioned to correctly grok computers in general. There are a LOT of users that have very, ummm, odd intellectual models of what's actually going on in there. Cue Tom Waits as appropriate. --\n-------------------------------------------------------------------\n* Jack Troughton jake at consultron.ca \n [link\|http://consultron.ca\|http://consultron.ca] [link\|irc://irc.ecomstation.ca\|irc://irc.ecomstation.ca] \n Kingston Ontario Canada [link\|news://news.consultron.ca\|news://news.consultron.ca] *\n-------------------------------------------------------------------
Post #225,461 by ChrisR 9/19/05 1:02:31 PM Reply	Programming Languages will influence the model So one must be careful to choose a PL that has the proper level of abstraction for the lesson to be taught and the model to be molded. If you want them to understand it in terms of bits and bytes and machine instructions, C and it's ilk is the way to go. If you want them to understand it as a set of libraries that can be slowly dissected, then Python and similar languages can be the way to go. Either way, both are really just models for the more abstract thought of network transport.
Post #225,468 by jake123 9/19/05 1:29:34 PM Reply	Indeed and I think a higher level view than C is the one for this. I might get a kick out of bit hacking from time to time, but I'm funny and strange. The key concept is two apps, one with a listen socket and one connecting to it, exchanging data through a series of read and write operations to their end of the socket. Once they grok that, then things like the output (in OS/2) of iptrace && ipformat get a lot easier to figure out. --\n-------------------------------------------------------------------\n* Jack Troughton jake at consultron.ca \n [link\|http://consultron.ca\|http://consultron.ca] [link\|irc://irc.ecomstation.ca\|irc://irc.ecomstation.ca] \n Kingston Ontario Canada [link\|news://news.consultron.ca\|news://news.consultron.ca] *\n-------------------------------------------------------------------
Post #225,481 by tjsinclair 9/19/05 3:03:14 PM Reply	Definitely want high level languages Keep this at the upper levels of the TCP/IP stack. Tom Sinclair Crowley was in Hell's bad books. Not that Hell has any other kind. -- (Terry Pratchett & Neil Gaiman, Good Omens)
Post #225,538 by Arkadiy 9/19/05 8:22:01 PM Reply	Yep. ------ 179. I will not outsource core functions. -- [link\|http://omega.med.yale.edu/~pcy5/misc/overlord2.htm\|.]

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