The Anarchist Cookbook (35 page)

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.