====================================================================== Paul's Guide to Using the Internet ====================================================================== Written for use at Northern Arizona University last update August 17, 1990 ====================================================================== There are three major functions of the Internet which are discussed in this paper: mail, ftp, telnet. Also covered are the Internet infor- mation utilities: nslookup, whois. There are many other services available such as using the talk util- ity to talk to people elsewhere on the Internet in real-time, and access to supercomputing resources, which will probably be covered another time. --------------------------------------- MAIL --------------------------------------- You can send electronic mail to anyone on the Internet from any Unix account on the computers in the College of Engineering. Unlike postal mail, "e-mail" is usually delivered within seconds. The mail command is usually typed like this: mail user@machine.dom.ain where "user" is the person you are sending mail to, and "machine.dom.ain" is the domain name of the computer their account is on. An example is shown below. (This form should work for any site on the Internet.) mail pab@mv3.cse.nau.edu If the message you send doesn't work for some reason, it will be returned to you with header information at the top describing what went wrong. A different type of long-distance mail is "UUCP" mail (Unix to Unix CoPy). This format is much slower because it uses ordinary telephone lines (it can take hours or days to deliver mail), and is also much less reliable than Internet mail. It is available for anyone to use, but it's use is generally discouraged. Sending mail to a UUCP address looks like: mail arizona!sitea!...!siteb!user where "user" is the person you are sending mail to, and "siteb" is the name of the computer they use. "arizona" and "sitea" are computers that are between you and them, which your mail must go through to get there. For NAU, "arizona" is almost always placed in front of any UUCP address, Page 1 Using the Internet August 17, 1990 since it is our only major out-bound UUCP contact (University of Arizona). mail arizona\!tom@gatekeeper.dec.com Notice that you must type a backslash "\" in front of all exclamation marks "!" if you are using the normal "C" shell. If you're in mail or you use a different Unix shell, you won't need to type backslashes here. If your mail keeps returning with an error and you can't figure out what is happening, you should show the complete message header to some- one who is more familiar with electronic mail. The system administrator of the Computer Science Unix area can usually help: Paul Balyoz 523-2088 e-mail address: root@naucse.cse.nau.edu (or: pab@naucse.cse.nau.edu) --------------------------------------- FTP --------------------------------------- FTP stands for "File Transfer Protocol". Ftp is also the name of the program you run when you want to copy files from or to another machine on the Internet. Ftp works by logging in to the remote com- puter, so you must have an account on that computer with a valid pass- word. Luckily, some machines on the Internet accept an "anonymous" ftp connection from any other site. This means you can type "anonymous" when asked for your login name, and then supply almost anything for the password since it isn't checked for validity. When using anonymous ftp it is recommended that you type something for the password that will identify you such as the login and machine name you're operating from, because these sites usually like to monitor outside connections. This is a common courtesy, not a requirement. An example password that you might use is: abc@mv1.cse.nau.edu where "abc" should really be your login name, and "mv3.cse.nau.edu" the machine you are running ftp from. NOTE: Many sites request that you do not use anonymous ftp on their machines during prime-time hours (8AM - 5PM) their time. Remember the different time zones in different parts of the country compared to us. For most of the U.S., after 5PM here is after 5PM there, unless the computer is in the Pacific Standard time zone (such as California), in which case they may be one hour behind us if it is daylight savings time there. (confusing enough?) Page 2 Using the Internet August 17, 1990 The actual command you would type is "ftp" with the domain name of the machine to connect to on the command line, as in: ftp megaron.cs.arizona.edu Occasionally hostnames such as this are not known to the system for some reason or another, in which case you must use the machine's numeric IP address. See the section on using "nslookup" for converting between a domain address and a numeric one. Example: ftp 128.196.128.118 If you get confused while using the ftp program, you should be able to type "?" or "help" and obtain a list of possible commands. You can always quit from ftp with the command "quit". Quitting will automati- cally close any connections you had with remote hosts. For futher information on using the ftp program, please read the manual page on this subject (type "man ftp" from unix). A sample ftp session to a machine at the University of Arizona in Tucson is shown below. The text to the right of the "ftp>" prompt is what was typed by the user. This "anonymous ftp" session will work for any host that accepts them. Read articles on Usenet to locate sites with this ability. rain-pab(33)- ftp megaron.cs.arizona.edu Connected to megaron.cs.arizona.edu. 220 megaron FTP server (Version 4.1 Sun Feb 12 16:06:59 PST 1989) ready. Name (megaron.cs.arizona.edu:pab): anonymous 331 Guest login ok, send ident as password. Password: 230 Guest login ok, access restrictions apply. ftp> cd pub 250 CWD command successful. ftp> dir 200 PORT command successful. 150 Opening ASCII mode data connection for /bin/ls (0 bytes). total 153 -rw-rw-r-- 1 28 wheel 316 Aug 17 03:12 README -rw-r--r-- 1 23 empty 141081 Aug 14 15:14 suffix.ps 226 Transfer complete. 138 bytes received in 0.32 seconds (0.42 Kbytes/s) ftp> get README 200 PORT command successful. 150 Opening ASCII mode data connection for README (316 bytes). 226 Transfer complete. local: README remote: README 324 bytes received in 0.03 seconds (11 Kbytes/s) ftp> close 221 Goodbye. ftp> ftp> quit Page 3 Using the Internet August 17, 1990 rain-pab(34)- cat README This is the "pub" directory for anonymous FTP from cs.arizona.edu. Transient files can be stored here without prior arrangement, by members of the computer science department. Please delete files after a successful transfer has been verified. Files in this directory are subject to deletion after 5 days. rain-pab(35)- --------------------------------------- TELNET --------------------------------------- Telnet is the protocol which allows you to remotely log in to another machine on the Internet. You see, "rsh" and "rlogin" which you may have used before are Unix-only commands; not every computer on the Internet supports them. But every Internet host is required to have the telnet protocol implemented. The name of the program you run is named after the protocol -- "telnet". Telnet works very similarly to ftp. However, there is no "anonymous" account for telnet; you must have an account on the remote machine and a working password, or it won't let you log in. Once you are logged in to the remote host it is just like you were sitting at a terminal connected to them directly; you are in your account using what- ever shell that account uses, and you can type any operating system com- mands just like normal. When you log out of that machine in the normal way, telnet sees that you've disconnected and exits. You are then back at your "local" host once again. Telnet enables you to access resources beyond your site. For instance, some organizations that need to mathematically manipulate com- plex sets of data or run simulations on large amounts of scientific research information can rent time on super-computers elsewhere in the United States, and connect up almost instantly using the Telnet program from their local computer or workstation no matter where they are located. As computers play a greater role in scientific research on campus, this feature will become increasingly important to professors and researchers who will find that they can do their job much more effec- tively than having to work simply with machines sitting in front of them (or located elsewhere on campus). The cost to buy a single supercom- puter is often in the tens or hundreds of millions of dollars, but rent- ing time is far more reasonable. Besides, the large transfer of data between machines that often must take place makes it prohibitive to con- nect up over a standard telephone line. Thus the Internet serves as an "invisible" transport for all kinds of information. For further information on using the telnet program, read the manual page on this subject ("man telnet"). Page 4 Using the Internet August 17, 1990 --------------------------------------- NAME LOOKUP --------------------------------------- One way you can explore the Internet is by using the nslookup util- ity. Some of the things you can do with it include: * Find out the numeric address of a machine from its domain name * Find out the domain name of a machine from its numeric address * Find out what kind of hardware and operating system a specific computer consists of * Find out what name servers exist for a given domain * Obtain a list of all machines in a domain from a name server To use it, simply type "nslookup" and press return. From that point there are many commands, a list of which you can get by typing a question-mark ("?") and pressing the return key. You must type an end- of-file character (CONTROL-D) to get out of nslookup. Although this program is often confusing to use, it comes in very handy when trying to track down a specific machine, or just to learn about the various domains and subdomains of the Internet. For simple name-to-address conversion you can do everything on the command line; for instance, nslookup megaron.cs.arizona.edu will print something like: Server: nau.edu Address: 134.114.64.14 Name: megaron.cs.arizona.edu Address: 192.12.69.1 The last two lines are the important ones: 192.12.69.1 is the IP address of the host you asked about, megaron.cs.arizona.edu. For more information on the nslookup utility, read the on-line manual page for it ("man nslookup"). --------------------------------------- NIC-NAME SITE INFORMATION --------------------------------------- Another interesting utility for exploring the Internet is the "whois" command, which allows you to query the domain registry database at the Network Information Center (NIC). You can ask it about any domain, network or sub-network on the Internet. You can also find Page 5 Using the Internet August 17, 1990 information on the various people who are in charge of those elements. Examples using the "whois" command: whois "university of arizona" [Use an organization's full name] whois berkeley.edu [Lists all known records about the domain "berkeley.edu"] whois BERKELEY-DOM [Describes a specific record about the "BERKELEY" domain] whois nau-net [Asks about the network named "nau-net"] whois balyoz [Asks about a person named "balyoz"] Queries regarding individuals can be done using all or part of their name, or by their NIC assigned handle. These handles completely distin- guish one entity from any other in the Internet registry. There are some special punctuation symbols to help be more selective about what kind of information is being sought. For detailed info on how to use "whois", please read the man-page, and then try the first example shown below which will tell you more than you ever wanted to know about "whois". Some other examples: whois help [Display a helpful document on the "whois" command] whois "ward, carol" [Ask about this person in specific] whois .gallagher [List all person records that have the name "gallagher" in them] whois \!LG70 [Tell about the person who has the handle "LG70". Note that you usually need a backslash before an exclamation mark.] whois zat... [Tell about anyone or anything that begins with the string "zat"] The information displayed regarding a person usually includes their full name, NIC handle, electronic mail address, postal address, and telephone number. These people are somehow involved in a part of the Internet, either administratively or technically. 9 9 Page 6 Using the Internet August 17, 1990 --------------------------------------- OTHER SERVICES --------------------------------------- Other services that the Internet makes available are such things as: * Multi-user discussion facilities * Highspeed distribution of Usenet News discussion groups * Interactive network (multiuser) games * Real-time "talk" between two users anywhere on the Internet * Mail gateways to other networks such as Bitnet, CSnet, SPAN, Fidonet, Compuserve, and to other countries in the world Further details will be given as the need and capability arises. ====================================================================== A good source of information regarding the Internet as a whole, or for learning which sites on the Internet support anonymous ftp, you should read Usenet News, available on the Unix Microvaxen in the College of Engineering. Usenet is a public message forum where the computer users can post messages and hold on-going discussions about many dif- ferent topics. Usenet contains many different newsgroups ordered by topic, some of which are: comp.mail.* Newsgroups about Internet mail comp.graphics Discussions of computer graphics news.announce.newusers Announcements for new users news.newusers.questions Questions/answers for new users comp.sys.mac Macintosh users comp.sys.ibm.pc IBM PC users comp.unix.* Newsgroups about UNIX topics to name just a few. There are currently more than 600 newsgroups, with more appearing all the time. You can read Usenet news if you have an account on one of the microvax computers in the College of Engineering. Information on accessing Usenet News is available in the Unix lab (Engineering room 137), or from Paul Balyoz whose office is Engineering room 133 (523-2088). 9 9 Page 7 -- _/\ _ !\ _ @ Milwaukee, WI - A Great Place by a Great Lake ! _! !! ! !_ ~~ @ ~ ~~ ! ! ! !! ! ! !~~__=||_~ ~~~ *** Computing Services Division *** ! ! ! _! ! ~~~ ~\____/ ~~~ yanoff@csd4.csd.uwm.edu yanoff@elvis.csd.uwm.edu