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Versions: 00 01                                                         
Internet Draft                                                 R. Plzak
Document: <draft-ietf-uswg-fyi7-00.txt>                            ARIN
                                                              G. Malkin
                                                        Nortel Networks
                                                          Walter Houser
                                                           October 2001

                      FYI on Questions and Answers
    Answers to Commonly asked "Experienced Internet User" Questions


Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026 [1].

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that
   other groups may also distribute working documents as Internet-
   Drafts. Internet-Drafts are draft documents valid for a maximum of
   six months and may be updated, replaced, or obsoleted by other
   documents at any time. It is inappropriate to use Internet- Drafts
   as reference material or to cite them other than as "work in
   The list of current Internet-Drafts can be accessed at
   The list of Internet-Draft Shadow Directories can be accessed at

1. Abstract

   This memo provides information to the experienced Internet user that
   wants to know more.  The term "experienced user" is used to
   differentiate this user from the new users addressed by FYI4.  The
   term experienced is relative. For the purpose of this memo
   _experienced_ is any user who is familiar with the concepts
   described in FYI 4.  The information provided in this memo is what
   may be described as an upper level or top level description of some
   of the applications and protocols that are in common use on the
   Internet today.  This memo does not provide precise technical
   descriptions.  For these the reader is referred to the appropriate
   RFC or other documentation.  A conscious effort has been made to
   keep this memo brief but at the same time provide the depth of
   information necessary to provide a general understanding of the
   applications and protocols described.

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2. Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   this document are to be interpreted as described in RFC-2119 [2].

3. Doing Things on the Internet or "How Does It Work?"

3.1. How does email work?

   Electronic mail is a lot like regular mail (also called snail mail)
   Your email message has a greeting to the addressee (or _to_ line), a
   subject, a body, a closing (or _from_ line), enclosures (also called
   attachments), carbon copies (cc), and blind carbon copies (bcc).
   After you write your message, your email software puts all this into
   an envelop with addressing information that repeats some of these
   same elements on the envelop. It then looks for a computer with a
   mail service called Simple Mail Transfer Protocol (SMTP), which
   serves like a mailbox outside your local post office.  The SMTP
   service passes your message to nearby SMTP computers (or servers)
   who know the destination computer (or domain) for your addressee. If
   any of these SMTP servers have trouble delivering your message, you
   will receive a delivery notice explaining the nature of the problem.
   Because email can be misunderstood or abused, users should be
   familiar with email netiquette.  For more information see Netiquette
   Guidelines [FYI 28, RFC 1855].

3.2. What is a Mailing List?

   A mailing list is a collection of email addresses of people
   interested in a topic like hobbies, product updates, work projects,
   and electronic newsletters.  Announcement lists go one way from the
   owner to the members. Discussion lists are two-way. Members send
   their messages to the list name at the mail list server (e.g. mail-
   list@listserver.com), which in turn distributes it to all members of
   a list. The list owner reviews messages sent to a moderated
   discussion list before they are released to the list. Messages to
   un-moderated discussion lists are not reviewed. You subscribe and
   unsubscribe using a separate email address for list maintenance, not
   the list address. Mail lists often have descriptions and procedures
   you should review before joining. Please stick to the list topic and
   use the list maintenance address to leave the list.

3.3. How does the World Wide Web work?

   Your web browser (Netscape, Internet Explorer, etc.) displays web
   pages located on various computers operating web servers. These web
   pages are written in Hypertext Markup Language (HTML) or extensible
   Markup Language (XML).  The web server sends the web pages and
   images to your PC using the Hypertext Transfer Protocol (HTTP). Your

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   web browser _renders_ the page, placing images and other page
   elements in their designated positions in the browser window.  As
   you move your cursor across the page, you should notice the cursor
   changes shape over what are called _hyperlinks._ Typically
   underlined and in blue, hyperlinks will take you to other web pages,
   on the same server or on any web server in the world. Pressing the
   hyperlink tells your browser to contact that destination web server
   for the next web page.

3.4. What is Instant Messaging?

   Many Internet service providers offer Instant messaging (IM) this
   popular tool for friends to keep in touch using the Internet. You
   announce your presence by entering your IM _handle_ or nickname into
   the IM pop-up window. You can use the same window to see your
   friends are online. Unlike chat (see below), IM is one-to-one; some
   chatters will have side conversations using IM. Many of the current
   IM protocols are not yet standardized so you may not be able to IM
   with someone on another service provider.

3.5. How do I send a lot of data across the Internet?

   Although you can send files or documents as attachments using email,
   most SMTP services limit the size or number of attachments. You can
   use a compression program to either reduce the size of a single
   attachment or combine several of them into one attachment.
   Depending on the nature of the attachment(s), its size can be
   reduced significantly. There are several compression programs that
   are available on the Internet - some are free.  If you routinely
   have to send a lot of files or a number of large files, you may want
   to contact your Internet Service Provider to gain access to an HTTP
   or FTP server. You can then send your addressees the location of the
   HTTP or FTP server, and they can download these files using FTP
   instead of clogging up email services with messages with large

4. Getting around the Internet

4.1.  What is an IP address?

   An Internet Protocol (IP) address is a binary number that is used to
   uniquely identify an Internet host.  It does not provide
   geographical information.  There are two versions of IP addresses in
   use on the Internet today - IPv4 and IPv6.  IPv4, the older version,
   is a 32-bit number.  It has been in use for many years but as the
   Internet grew there arose concerns about there being enough to go
   around so the newer 128-bit IPv6 version was developed. IPv6 is in
   the early stages of use so the Internet continues to use IPv4
   addresses.  The 32-bit IPv4 address is divided into 4 bytes.  In
   decimal notation each byte is separated by a dot so that a typical

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   address looks like this: The 128 bits of the IPv6
   address are divided into eight (8) groups of 16 bits.  The groups
   are separated by a colon and are written in hexadecimal notation.
   An IPv6 address looks like this:
   FEDC:BA98:7654:3210:FEDC:BA98:7654:3210.  Thankfully users don't
   have to remember IP addresses to use the Internet - the Domain Name
   System (DNS) translates easily remembered names to addresses.

4.2. What is a packet?

   The word "packet" may be used to reference any unit of transmittable
   information where the actual layer associated with the packet is
   either implicit or unimportant.  A packet on the wire is properly
   referred to as a frame.  A network layer (IP) packet is called a
   datagram (the name was coined by Jon Postel).  A transport layer
   (TCP or UDP) packet is called a segment.  The packet that the
   application hands to the network for transmission, is called a

4.3. What is a router?

   A device which forwards traffic between (sub)networks based on layer
   3 (network layer) information.  The routing decision is based on
   information maintained in routing tables, often constructed by
   routing protocols.  Routers used to be referred to as gateways,
   which is currently too generic a term.  Properly, a router is a
   layer-3 gateway.  A bridge, by way of example, is a layer-2 gateway.
   Routing is the process of determining the correct path for a packet.
   Forwarding is the process by which a packet is received on one
   interface and transmitted on another.

4.4. How are packets routed?

   When a packet (more properly, a datagram) is received on a router's
   interface, its IP header is examined.  If it fails any of several
   validity checks, it is discarded and an ICMP error message is
   (usually) sent to the originator of the datagram.  The datagram's
   destination address is then examined.  If it specifies one of the
   router's local addresses, or it is a broadcast, it is delivered to
   the handler for the protocol specified in the header.  If it is a
   multicast, it may be delivered locally (if the router is receiving
   that specific address).  It may also be forwarded according to the
   set of rules or routing information governing that multicast
   address.  If the datagram is for any other destination, the best
   path to that destination (more specifically, the next hop on the
   path) is determined and the packet is sent out the interface that
   leads to that next hop.  The determination of the best path (for
   unicast and multicast) datagrams is made based on information in the
   router's routing tables.  That table is populated by configured

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   information (e.g., static routes), or learned information from a
   routing protocol (e.g., RIP, OSPG, BGP-4).  In most routers, routing
   information for unicast and multicast routes are kept in separate
   tables and populated using different routing protocols.  For unicast
   destinations, there are several types of routes: host, subnet,
   network, supernet and default.  Each type of route is less specific
   than the one before it.  For example, a host route specifies one and
   only one host (i.e., its subnet mask is, while a
   subnet route points to all of the hosts on a specific subnet.  The
   default route specifies the path for a datagram for which no other
   type of route is available.  This hierarchy is referred to as
   longest match because the preference is for routes which have longer
   (i.e., more 1-bits) subnet masks, the default route having a mask of

4.5. What is DNS?

   DNS is the Domain Name System.  It is a mechanism by which host
   names can be converted (resolved) into Internet addresses.  A Fully
   Qualified Domain Name (FQDN) has two parts: the hostname, which is
   unique within the domain; and the domain name, which is globally
   unique.  For example, atlas.supports.world.com has "atlas" as a
   hostname and "supports.world.com" as a domain name.  The domain name
   is also made of multiple parts.  In this example, "com" is the Top
   Level Domain (TLD), "world" is the domain assigned out of com, and
   "supports" is a sub-domain chosen by the owner of world.  There may
   be zero or more sub-domains.  The TLD is the space from which the
   domain is assigned.  Contrary to popular belief, there are more
   domains than com.  Originally, "com" was used for vendors that
   created networking hardware and software; today, it has become the
   catchall for domain trash.  Fortunately, the other domains (except,
   perhaps, "net" and _org_) have managed to retain their original
   intents.  "Net" is for service provider  networks (e.g., ISPs).
   "Org" is for non-profit organizations.  The other TLDs have far more
   rigid controls.  "Edu" is for 4-year colleges (although some 2-year
   institutions were grand fathered in).  "Mil" is the U.S. military,
   and "gov" is the
   U.S. government.  Two-letter TLDs are country codes (e.g., "us" for
   the United States, "au" for Australia).  The sub-domains under the
   country domains are managed by their respective countries.  In the
   U.S., for example, there is one sub-domain for each state (e.g.,
   "ma.us" for Massachusetts, "ny.us" for New York).

4.6. How does DNS work?

   The Domain Name System consists of a group of computers called name
   servers.  These servers contain a special file called a zone file
   that contains the information necessary to resolve the names of the
   hosts in the domain into IP addresses or provide a reference to the
   location of the zone file for a subdomain.   These servers are
   related to each other in the same hierarchical manner as the domains

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   they support.  Names are resolved to numbers in the following

   The application that is requesting the resolution of a name to an IP
   address contacts its local server.  If the local server knows the
   answer it provides it to the requestor.  If it does not, it must
   seek the answer elsewhere.

   The search begins at the top of DNS tree, the root.  The local
   server asks the root server for the answer.  The root server
   provides a partial answer, in that it will identify the servers for
   the TLD that contains the name.  The local server then asks the TLD
   server for the answer.  The TLD server provides a partial answer.
   It identifies the servers for the subdomain of TLD that contains the
   name.  The search continues in a similar manner until the server
   that has the zone file that contains the entire name is located.
   This server then provides the IP number.

4.7. What is an intranet?

   An intranet is a collection of networks that may or may not be
   connected to the Internet.  Generally, an intranet is maintained and
   administered by an organization that may be a commercial firm or a
   government organization.  If the intranet is connected to the
   Internet it is usually done at selected points that control access
   from the intranet to the Internet and control access from the
   Internet to the intranet.  Typically, only certain services such as
   email are permitted to flow across these control points.

4.8. What is Tunneling?

   Tunneling is the term applied to establishing an end-to-end
   connection for the purpose of providing protected transfer of
   information across the Internet.  One typical method of doing this
   is encrypt packets at the transmission end and decrypt them at the
   reception end.

5.  Security Considerations

5.1 How do I protect my personal information when I surf the Internet?

   The ubiquitous nature of the Internet has resulted in widespread
   concern for the loss of personal privacy. Once your privacy is
   compromised, you cannot get it back. The US Federal Trade Commission
   http://WWW.FTC.GOV has established voluntary Fair Information
   Practices covering notice, consent, access and security.  The FTC
   surveyed over 300 web sites that collect personal information and
   found that only 20 percent discussed all four elements.  In a sample
   of more popular web sites, only 42 percent covered all four elements
   of privacy protection.  The FTC found that the bankrupt eCommerce

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   vendor Toysmart violated the FTC Act by attempting to sell customer
   data after claiming that this data would never be disclosed to a
   third party. Criminals can use your personal data to steal your
   identity and credit rating. California Public Interest Research
   Group found that victims spent between two and four years removing
   an average of $18,000 in fraudulent card charges charges.  Reputable
   sites should tell you how they are protecting your information by
   adhering to the FTC's recommended practices. If any of their
   statements make you uncomfortable, leave the items blank or enter
   imaginary data. If you do enter your data, print the notice for your
   files in case it is violated.

5.2 What steps should I take to protect myself when shopping on the

   Know the vendor you are dealing with. Only enter credit card
   information when suing a secure connection to the merchant; look for
   the little padlock at the bottom of your web browser. US citizens
   should use a credit card because US law limits your liability for
   unauthorized charges to $50 dollars.  Debit cards do not have such a
   limit. Use a credit card with a low credit limit.  Check your credit
   history periodically with credit bureaus; thieves can open new
   accounts using your stolen personal data unbeknownst to you. The US
   Federal Trade Commission http://www.ftc.gov offers valuable

   additional suggestions for online shoppers.
6. References

   [1] Bradner, S., "The Internet Standards Process -- Revision 3", BCP
       9, RFC 2026, October 1996.

   [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
       Levels", BCP 14, RFC 2119, March 1997.

   [3] Hambridge, S. "Netiquette Guidelines", RFC 1855, October 1995.

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7. Author's Addresses

   Raymond Plzak
   4506 Daly Drive, Suite 200
   Chantilly, VA 20151
   Phone: +1.703.227.9850
   Email: plzak@arin.net

   Gary Malkin
   Nortel Networks
   600 Tech Park
   Billerica, MA 01621
   Phone: +1.978.288.3684
   Email: gmalkin@nortelnetworks.com

   Walter Houser
   Program Coordination Staff (045APC)
   Department of Veterans Affairs
   810 Vermont Avenue
   Washington DC  20420
   Email: houser.walt@forum.va.gov

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   This document and the information contained herein is provided on an

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