INLS261 Tools for Information Literacy

[intro] [clients] [servers] [networks] [internet]
[open source] [telnet] [file transfer] [UNIX network tools] [subtask 1.5] [bookmarks] [next time]

[student] [topical] [radio] [newsletter] [interest] [policy]

Using UNIX to get Internet answers

To login, you need to make a telnet connection to the ISIS server.

SILS uses a telnet client program called "SSH", but you can use other clients, too.
SSH uses ssh (the Secure Shell) to login, so that your username and password are not visible to other people on the campus network.

To login from your computer (it's the same here in the lab or elsewhere on your laptop):

Start the program (from your desktop, the Start menu, or from the Run dialog box)
Select "Quick Connect", then enter isis.unc.edu in the dialog box and enter your onyen.
Accept & Save the host key, if requested. (This is the encryption key that lets Isis identify itself).
You will be prompted for your username & password; provide them.
If desired, you can cause SSH to remember your session, and make various changes to the session settings (like the screen colors)
I'd recommend that you do this only if you are using your own computer (for security reasons)

Once there, select <6> to get into a shell session and thus into UNIX. The $ is the UNIX prompt.

To logout when you're done (don't forget to do this!):
Type <exit> if you are at the shell prompt [the $] instead of the menu
or, select the logout option from the menu

[top]

Internet tools available in UNIX and elsewhere (DOS, Windows)

As we discussed during the Internet session, the Domain Name System [DNS] operates behind the scenes. We don't need to know an IP address for a particular hostname, and don't need to worry about how the data get from one place to another. For experts, though, it's good to be able to get behind the scenes to diagnose problems or errors.

Utilities available for UNIX/Linux and Windows machines, among others, include ping, traceroute, nslookup and whois.

[top]

Try them out using UNIX:

<whois unc.edu> gets basic information about the DNS servers for unc.edu
<whois -h whois.networksolutions.com unc.edu> gets more detailed information including the administrative, technical, billing and zone contact
- There are other registrars than networksolutions.com, but they were one of the first.
- whois can help you to find out where to go to find out about the human organization on the other side of a hostname.
<ping some URL> like <ping www.yahoo.com>
- sends a ICMP packet over the IP to check whether a host is alive, and how quickly a response is received.
- On Isis and some other systems, use <ping -s www.yahoo.com> then <CNTL+C> to cancel.
<nslookup www.state.gov> gets the IP address(es) associated with the hostname www.state.gov.
- Some sites have more than one IP address for redundancy or load-handling (try www.whitehouse.gov or www.yahoo.com).
<traceroute www.google.com> traces the route your packets take to get to www.google.com.
- This can be thrown off by firewalls or other systems that block some types of packets.
- <CNTL+C> to cancel

[top]

Try out WHOIS in UNIX and on the Web

You can also use and telnet tool to find out something about web domains by using the UNIX command "whois". In this example, I used SecureCRT. You can use SSH if you prefer.

Log into ISIS using SecureCRT and your ONYEN/password combination, exactly as you did it using Telnet. You will see the same screen.
Select 6 to start a UNIX session. At the $ prompt, enter the command whois and the name of the domain you are interested in.
The command will then search the Internic database and tell you who registered the name and who the name server is.
- In this case, I want to know the name and address of the person who has that name, so I will need to use another WHOIS tool.
you can also find out more detailed domain ownership information by using one of the web-based whois applications
- you can also find out data from the whois database by checking Network Solutions or Better Whois
- You can find out more about whois by checking with whatis?

[top]

Try out Traceroute a bit more

We want to use Traceroute to see how long it takes to send a signal to a remote server and have it return to ISIS.

The traceroute program is used to determine the path that messages might take from one machine to another. Recall that any packet (message) sent on the Internet must go through some number of routers to get to its destination. Each link in this path is called a hop. Local traffic usually has very few hops (zero or 1 or 2) while long-distance traffic can take thirty or more hops before arriving. Traceroute lets us look at the path a message might take through this chain of routers to get to its destination.

Using a simple telnet tool [not SSH], I ran one traceroute to europa.eu.int to see what it got me. I could see it first told me the site's IP address (expressed in numbers) and then showed me all the jumps from ATN's ISIS server through switches at CiscoKid, on to RTP, then onto the Internet backbone through several different backbone providers (AlterNet, UUNet [part of WorldCom], UUNet in Belgium, among others, and on to the final destination. In this case, it took over 30 hops to get there.

I then ran a second traceroute to www.sandhills.net which is in Southern Pines, NC (about 75 miles away), and it took 11 hops to get there, mostly through Sprint switches.

Try it out on sites you are curious about. Look at the path the connection follows and how long each segment takes.

When you are finished, type in the command <exit> and then select option 8 to close your link to ISIS

The above procedure allows you to run traceroute on a Unix server, but you can also run it on a Windows PC

The DOS way to run Traceroute is to go to start and then open the run dialog box

then type in <cmd> for a command prompt.

Once you have the command prompt, type the command <tracert> followed by the internet address

However, fully typing the word <command> will get you to the command prompt on all windows boxes

Consider adding SSH or WS_FTP to your computer for FTP applications

[top]