ICS 54: Brief Notes on Chapter 13: The Internet

References

http://www.zakon.org/robert/internet/timeline/

Hobbes' Internet Timeline

http://freesoft.org/CIE/

Connected: An Internet Encyclopedia

http://www.whatis.com/tour.htm

An overview of the Internet from http://www.whatis.com/

http://www.it.kth.se/docs/rfc/

KTH (Sweden) RFC Archive

http://www.garlic.com/~lynn/rfcietff.htm

Lynn Wheeler's IETF RFC Index

http://www.dns.net/dnsrd/

DNS Resources Directory

http://www.w3.org/

W3C = World Wide Web Consortium

Name Resolution

• Given a network system name, determine the corresponding IP address.
• Translate network system names to corresponding IP addresses.
• Map network system names to corresponding IP addresses.

There are three different methods in use to accomplish this task (possibly used in combination):

Static table(s).

In Unix, this is stored in /etc/hosts. This was originally how the Internet worked.

Network Information Service (NIS)

Formerly called Yellow Pages (YP), this was originated by Sun along with NFS (Network File System).

Domain Name System (DNS).

This is the current Internet approach, so you have to use it if you're "on the Net."

DNS

Primarily, it holds name<-->address mappings and mail routing information.

DNS was formally specified in RFCs 882 & 883 (November 1983) by Paul Mockapetris, who got his PhD from UCI ICS.
In November 1987, these RFCs superceded by 1034 & 1035, also written by Mockapetris, which remain in force as Internet Standard 13.

The specification includes both a hierarchical host naming scheme and a protocol for performing various operations, such as mapping a name to an address.

The top-level domain is the "root" domain, named "." (yes, just "."="dot").

See DNS Resources Directory (http://www.dns.net/dnsrd/) and
(http://www.freesoft.org/CIE/Course/Section2/) from Connected: An Internet Encyclopedia.

Domain Names

For instance, www.taa.com's address is 206.86.53.211, while rd.taa.com's address is 204.140.196.3. They're several hundred miles apart.

Domain names are case insensitive.
You can't easily distinguish a hostname from a domain name: taa.com is both a host named taa in the com domain.
It's also a domain name in which other hostnames live.
Potentially, other domain names could exist under taa.com as well.

A domain name doesn't necessarily map to an IP network number: it may map to many or to none at all.

nslookup

server host

Use host as the server.

set type=type

Set the query type, such as "mx", "ns", "a", etc.

name

Show the type information for name.

nslookup Examples

Default Server:  elliotgw.ics.uci.edu
Address:  128.195.6.4

> ics.uci.edu
Server:  elliotgw.ics.uci.edu
Address:  128.195.6.4

Name:    ics.uci.edu
Address:  128.195.1.1

> set type=mx
> ics.uci.edu
Server:  elliotgw.ics.uci.edu
Address:  128.195.6.4

ics.uci.edu     preference = 10, mail exchanger = ics.uci.edu
ics.uci.edu     preference = 20, mail exchanger = paris.ics.uci.edu
ics.uci.edu     internet address = 128.195.1.1
paris.ics.uci.edu       internet address = 128.195.1.50

> set type=ptr
> 1.1.195.128.in-addr.any
Server:  elliotgw.ics.uci.edu
Address:  128.195.6.4

1.1.195.128.in-addr.arpa        name = ics.uci.edu

Finding Root Servers with nslookup

> set type=ns
> server ns.nasa.gov
Default Server:  ns.nasa.gov
Addresses:  128.102.16.10, 192.52.195.10, 192.203.230.10

> .
Server:  ns.nasa.gov
Addresses:  128.102.16.10, 192.52.195.10, 192.203.230.10

(root)  nameserver = H.ROOT-SERVERS.NET
(root)  nameserver = B.ROOT-SERVERS.NET
(root)  nameserver = C.ROOT-SERVERS.NET
(root)  nameserver = D.ROOT-SERVERS.NET
(root)  nameserver = E.ROOT-SERVERS.NET
(root)  nameserver = I.ROOT-SERVERS.NET
(root)  nameserver = F.ROOT-SERVERS.NET
(root)  nameserver = G.ROOT-SERVERS.NET
(root)  nameserver = A.ROOT-SERVERS.NET
H.ROOT-SERVERS.NET      internet address = 128.63.2.53
B.ROOT-SERVERS.NET      internet address = 128.9.0.107
C.ROOT-SERVERS.NET      internet address = 192.33.4.12
D.ROOT-SERVERS.NET      internet address = 128.8.10.90
E.ROOT-SERVERS.NET      internet address = 192.203.230.10
I.ROOT-SERVERS.NET      internet address = 192.36.148.17
F.ROOT-SERVERS.NET      internet address = 192.5.5.241
G.ROOT-SERVERS.NET      internet address = 192.112.36.4
A.ROOT-SERVERS.NET      internet address = 198.41.0.4

dig

See http://www.freesoft.org/CIE/Course/Section2/13.htm for a web form of dig.

There are also web forms of whois and nslookup

USENET News Groups

Now it is more often considered simply as that collection of information known as news/netnews organized (hierarchically) into "newsgroups."

USENET uses Network News Transfer Protocol (NNTP) as described in RFC 997 (1986).

News can be read and posted via a number of different clients, including both special purpose ones (e.g., rn, trn) and clients which also access e-mail or (even more generally) the web.

Mailing lists

• listserv and its close relative listproc
• Majordomo

• LWGate
• Mailman
• egroups

IRC

For example, here is an excerpt from http://www.irchelp.org/irchelp/altircfaq.html:

What is IRC?

IRC stands for "Internet Relay Chat". It was originally written by Jarkko Oikarinen (jto@tolsun.oulu.fi) in 1988. Since starting in Finland, it has been used in over 60 countries around the world. It was designed as a replacement for the "talk" program but has become much much more than that. IRC is a multi-user chat system, where people convene on "channels" (a virtual place, usually with a topic of conversation) to talk in groups, or privately. IRC is constantly evolving, so the way things to work one week may not be the way they work the next. Read the MOTD (message of the day) every time you use IRC to keep up on any new happenings or server updates.

IRC gained international fame during the 1991 Persian Gulf War, where updates from around the world came accross (sic) the wire, and most irc users who were online at the time gathered on a single channel to hear these reports. IRC had similar uses during the coup against Boris Yeltsin in September 1993, where IRC users from Moscow were giving live reports about the unstable situation there.

How is IRC set up?

The user runs a "client" program (usually called 'irc') which connects to the irc network via another program called a "server". Servers exist to pass messages from user to user over the irc network.

Archie, Gopher, Veronica, Jughead, ...

Archie

A way of searching ftp (archi(v)e) sites

Gopher

A menu oriented precursor to the web from the University of Minnesota

Veronica
("Very Easy, Rodent-Oriented, Net-Wide Index to Computerized Archives")

A way of searching gopher sites from University of Nevada, Reno

Jughead
("Jonzy's Universal Gopher Hierarchy Excavation And Display")

A more limited way of searching gopher sites than Veronica. From University of Utah.

The Web

Its Roots

What Does W3 Define?

These include

• The idea of a boundless information world in which all items have a reference by which they can be retrieved;
• The address system (URI) ... implemented to make this possible, despite many different protocols;
• A network protocol (HTTP) ... giving performance and features not otherwise available;
• A markup language (HTML) ... used for the transmission of basic things ... across the net;
• The body of data available on the Internet using all or some of the preceding listed items.

From "The World-Wide Web,"
by T. Berners-Lee, R. Cailliau, et al.,
Communications of the ACM,
v.37, No.8, Aug 1994, pp. 76-82.

How it Works

More Information