fucked up slightly and called one too many 800 lines.
Right now, after all of that, you should have a pretty good idea of how to grow up as a good
phreak. Follow these guidelines, don't show off, and don't take unnecessary risks when
phreaking or hacking.
122.Phrack Magazine - Vol. 3, Issue 27 by Knight Lightning
If you are not already familiar with NSFnet, I would suggest that you read: "Frontiers"
(Phrack Inc., Volume Two, Issue 24, File 4 of 13), and definitely; "NSFnet: National
Science
Foundation Network" (Phrack
Inc., Volume
Three,
Issue 26, File 4 of 11).
MIDNET is a regional computer network that is part of the NSFnet, the National
Science Foundation Network. Currently, eleven mid-United States universities
are connected to each other and to the NSFnet via MIDnet:
UA - University of Arkansas at Fayetteville
ISU - Iowa State University at Ames
UI - University of Iowa at Iowa City
KSU - Kansas State University at Manhattan
KU - University of Kansas at Lawrence
UMC - University of Missouri at Columbia
WU - Washington University at St. Louis, Missouri
UNL - University of Nebraska at Lincoln
OSU - Oklahoma State University at Stillwater
UT - University of Tulsa (Oklahoma)
OU - University of Oklahoma at Norman
Researchers at any of these universities that have funded grants can access the
six supercomputer centers funded by the NSF:
John Von Neuman Supercomputer Center
National Center for Atmospheric Research
Cornell National Supercomputer Facility
National Center for Supercomputing Applications
Pittsburgh Supercomputing Center
San Diego Supercomputing Center
In addition, researchers and scientists can communicate with each other over a vast
world-wide computer network that includes the NSFnet, ARPAnet, CSnet, BITnet, and
others that you have read about in The Future Transcendent Saga. Please refer to
"Frontiers" (Phrack Inc., Volume Two, Issue 24, File 4 of 13) for more details.
MIDnet is just one of several regional computer networks that comprise the NSFnet
system. Although all of these regional computer networks work the same, MIDnet is the
only one that I have direct access to and so this file is written from a MIDnet point of
view. For people who have access to the other regional networks of NSFnet, the only real
differences depicted in this file that would not apply to the other regional networks are
the universities that are served by MIDnet as opposed to:
NYSERnet in New York State
SURAnet in the southeastern United States
SEQSUInet in Texas
BARRnet in the San Francisco area
MERIT in Michigan
(There are others that are currently being constructed.)
These regional networks all hook into the NSFnet backbone, which is a network that
connects the six supercomputer centers. For example, a person at Kansas State University
can connect with a supercomputer via MIDnet and the NSFnet backbone. That researcher
can also send mail to colleagues at the University of Delaware by using MIDnet, NSFnet
and SURAnet. Each university has its own local computer network which connects on-
campus computers as well as providing a means to connecting to a regional network.
Some universities are already connected to older networks such as CSnet, the ARPAnet
and BITnet. In principal, any campus connected to any of these networks can access
anyone else in any other network since there are gateways between the networks.
Gateways are specialized computers that forward network traffic, thereby connecting
networks. In practice, these wide-area networks use different networking technology
which make it impossible to provide full functionality across the gateways. However, mail is
almost universally supported across all gateways, so that a person at a BITnet site can
send mail messages to a colleague at an ARPAnet site (or anywhere else for that matter).
You should already be somewhat familiar with this, but if not refer to; "Limbo To Infinity"
(Phrack Inc., Volume Two, Issue 24, File 3 of 13) and "Internet Domains" (Phrack Inc.,
Volume Three, Issue 26, File 8 of 11)
Computer networks rely on hardware and software that allow computers to communicate.
The language that enables network communication is called a protocol. There are many
different protocols in use today. MIDnet uses the TCP/IP protocols, also known as the
DOD (Department of Defense) Protocol Suite.
Other networks that use TCP/IP include ARPAnet, CSnet and the NSFnet. In fact, all the
regional networks that are linked to the NSFnet backbone are required to use TCP/IP. At
the local campus level, TCP/IP is often used, although other protocols such as IBM's SNA
and DEC's DECnet are common. In order to communicate with a computer via MIDnet and
the NSFnet, a computer at a campus must use TCP/IP directly or use a gateway that will
translate its protocols into TCP/IP.
The Internet is a world-wide computer network that is the conglomeration of most of the
large wide area networks, including ARPAnet, CSnet, NSFnet, and the regionals, such as
MIDnet. To a lesser degree, other networks such as BITnet that can send mail to hosts on
these networks are included as part of the Internet. This huge network of networks, the
Internet, as you have by now read all about in the pages of Phrack Inc., is a rapidly growing
and very complex entity that allows sophisticated communication between scientists,
students, government officials and others. Being a part of this community is both exciting
and challenging.
This chapter of the Future Transcendent Saga gives a general description of the protocols
and software used in MIDnet and the NSFNet. A discussion of several of the more
commonly used networking tools is also included to enable you to make practical use of the
network as soon as possible.
The DOD Protocol Suite
The DOD Protocol Suite includes many different protocols. Each protocol is a specification
of how communication is to occur between computers. Computer hardware and software
vendors use the protocol to create programs and sometimes specialized hardware in order
to implement the network function intended by the protocol. Different implementations of
the same protocol exist for the varied hardware and operating systems found in a network.
The three most commonly used network functions are:
Mail -- Sending and receiving messages
File Transfer -- Sending and receiving files
Remote Login -- Logging into a distant computer
Of these, mail is probably the most commonly used.
In the TCP/IP world, there are three different protocols that realize these
functions:
SMTP -- (Simple Mail Transfer Protocol) Mail
FTP -- (File Transfer Protocol) sending and receiving files
Telnet -- Remote login
How to use these protocols is discussed in the next section. At first glance, it is not
obvious why these three functions are the most common. After all, mail and file transfer
seem to be the same thing. However, mail messages are not identical to files, since they
are usually comprised of only ASCII characters and are sequential in structure. Files may
contain binary data and have complicated, non-sequential structures. Also, mail messages
can usually tolerate some errors in transmission whereas files should not contain any
errors. Finally, file transfers usually occur in a secure setting (i.e. The users who are
transferring files know each other's names and passwords and are permitted to transfer
the file, whereas mail can be sent to anybody as long as their name is known).
While mail and transfer accomplish the transfer of raw information from one computer to
another, Telnet allows a distant user to process that information, either by logging in to a
remote computer or by linking to another terminal. Telnet is most often used to remotely
log in to a distant computer, but it is actually a general-purpose communications protocol.
I have found it incredibly useful over the last year. In some ways, it could be used for a
great deal of access because you can directly connect to another computer anywhere that
has TCP/IP capabilities, however please note that Telnet is *NOT* Telenet. There are
other functions that some networks provide, including the following:
Name to address translation for networks, computers and people
The current time
Quote of the day or fortune
Printing on a remote printer, or use of any other remote peripheral
Submission of batch jobs for non-interactive execution
Dialogues and conferencing between multiple users
Remote procedure call (i.e. Distributing program execution over several remote
computers)
Transmission of voice or video information
Some of these functions are still in the experimental stages and require faster computer
networks than currently exist. In the future, new functions will undoubtedly be invented
and existing ones improved.
The DOD Protocol Suite is a layered network architecture, which means that network
functions are performed by different programs that work independently and in harmony
with each other. Not only are there different programs but there are different protocols.
The protocols SMTP, FTP and Telnet are described above. Protocols have been defined for
getting the current time, the quote of the day, and for translating names. These protocols
are called applications protocols because users directly interact with the programs that
implement these protocols.
The Transmission Control Protocol, TCP, is used by many of the application protocols.
Users almost never interact with TCP directly. TCP establishes a reliable end-to-end
connection between two processes on remote computers. Data is sent through a network in
small chunks called packets to improve reliability and performance. TCP ensures that
packets arrive in order and without errors. If a packet does have errors, TCP requests
that the packet be retransmitted.
In turn, TCP calls upon IP, Internet Protocol, to move the data from one network to
another. IP is still not the lowest layer of the architecture, since there is usually a "data
link layer protocol" below it. This can be any of a number of different protocols, two very
common ones being X.25 and Ethernet.
FTP, Telnet and SMTP are called "application protocols", since they are directly used by
applications programs that enable users to make use of the network. Network applications
are the actual programs that implement these protocols and provide an interface between
the user and the computer. An implementation of a network protocol is a program or
package of programs that provides the desired network function such as file transfer.
Since computers differ from vendor to vendor (e.g. IBM, DEC, CDC), each computer must
have its own implementation of these protocols. However, the protocols are standardized
so that computers can interpolate over the network (i.e. Can understand and process each
other's data). For example, a TCP packet generated by an IBM computer can be read and
processed by a DEC computer.
In many instances, network applications programs use the name of the protocol. For
example, the program that transfers files may be called "FTP" and the program that allows
remote logins may be called "Telnet." Sometimes these protocols are incorporated into
larger packages, as is common with SMTP. Many computers have mail programs that allow
users on the same computer to send mail to each other. SMTP functions are often added
to these mail programs so that users can also send and receive mail through a network. In
such cases, there is no separate program called SMTP that the user can access, since the
mail program provides the user interface to this network function.
Specific implementation of network protocols, such as FTP, are tailored to the computer
hardware and operating system on which they are used. Therefore, the exact user
interface varies from one implementation to another. For example, the FTP protocol
specifies a set of FTP commands which each FTP implementation must understand and
process. However, these are usually placed at a low level, often invisible to the user, who
is given a higher set of commands to use.
These higher-level commands are not standardized so they may vary from one
implementation of FTP to another. For some operating systems, not all of these commands
make equal sense, such as "Change Directory," or may have different meanings. Therefore
the specific user interface that the user sees will probably differ.
This file describes a generic implementation of the standard TCP/IP application protocols.