rfc1207.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

Network Working Group                                          G. Malkin
Request for Comments: 1207                            FTP Software, Inc.
FYI: 7                                                         A. Marine
                                                                     SRI
                                                             J. Reynolds
                                                                     ISI
                                                           February 1991


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

Status of this Memo

   This FYI RFC is one of two FYI's called, "Questions and Answers"
   (Q/A), produced by the User Services Working Group of the Internet
   Engineering Task Force (IETF).  The goal is to document the most
   commonly asked questions and answers in the Internet.

   This memo provides information for the Internet community.  It does
   not specify any standard.  Distribution of this memo is unlimited.

Table of Contents

   1. Introduction..................................................  1
   2. Acknowledgements..............................................  3
   3. Questions about the Internet..................................  3
   4. Questions About Other Networks and Internets..................  3
   5. Questions About Internet Documentation........................  4
   6. Questions About the Domain Name System (DNS)..................  4
   7. Questions About Network Management............................  7
   8. Questions about Serial Line Internet Protocol (SLIP) and
      Point-to-Point Protocol (PPP) Implementations.................  9
   9. Questions About Routing....................................... 11
   10. Other Protocol and Standards Implementation Questions........ 11
   11. Suggested Reading............................................ 12
   12. References................................................... 13
   13. Security Considerations...................................... 14
   14. Authors' Addresses........................................... 15

1. Introduction

   During the last few months, several people have monitored various
   major mailing lists and have extracted questions that are important
   or commonly asked.  This FYI RFC is one of two in a series of FYI's
   which present the questions and their answers.  The first FYI, FYI 4,
   presented questions new Internet users commonly ask and their
   answers.



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RFC 1207        FYI Q/A - for Experienced Internet Users   February 1991


   The goal of this FYI is to codify the Internet lore so that network
   operations staff, especially for networks just joining the Internet,
   will have an accurate and up to date set of references from which to
   work.  Also, redundancies are moved away from the electronic mailing
   lists so that the lists' subscribers do not have to read the same
   queries and answers over and over again.

   Although the questions and their responses are taken from various
   mailing lists, they are presented here loosely grouped by related
   topic for ease of reading.  First the question is presented, then the
   answer (or answers) as it appeared on the mailing list.

   Sometimes the answers are abridged for better use of space.  If a
   question was not answered on the mailing list, the editors provide an
   answer.  These answers are not distinguished from the answers found
   on the lists.  Sometimes, in order to be as complete as possible, the
   editors provide additional information that was not present in the
   original answer.  If so, that information falls under the heading
   "Additional Information".

   The answers are as correct as the reviewers can make them.  However,
   much of this information changes with time.  As the FYI is updated,
   temporal errors will be corrected.

   Many of the questions are in first person, and the answers were
   directed to the originator of the question.  These phrasings have not
   been changed except where necessary for clarity.  References to the
   correspondents' names have been removed.

   The Q/A mailing lists are maintained by Gary Malkin at FTP.COM.  They
   are used by a subgroup of the User Services Working Group to discuss
   the Q/A FYIs.  They include:

   [e-mail]           This is a discussion mailing list.  Its
                           primary use is for pre-release review of
                           the Q/A FYIs.

   [e-mail]   This is how you join the quail mailing list.

   [e-mail]       This is where the questions and answers
                           will be forwarded-and-stored.  It is
                           not necessary to be on the quail mailing
                           list to forward to the quail-box.








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RFC 1207        FYI Q/A - for Experienced Internet Users   February 1991


2. Acknowledgments

   The following people deserve thanks for their help and contributions
   to this FYI Q/A: Jim Conklin (EDUCOM), John C. Klensin (MIT),
   Professor Kynikos (Special Consultant), Jon Postel (ISI),
   Marshall Rose (PSI, Inc.), David Sitman (Tel Aviv University),
   Patricia Smith (Merit), Gene Spafford (Purdue), and
   James Van Bokkelen (FTP Software, Inc.).

3. Questions about the Internet

   3.1. How do I get statistics regarding the traffic on NSFNET?

      Merit/NSFNET Information Services maintains a variety of
      statistical data at 'nis.nsf.net' (35.1.1.48) in the 'stats'
      directory.  Information includes packet counts by NSS and byte
      counts for type of use (ftp, smtp, telnet, etc.).  Filenames are
      of the form 'NSFyy-mm.type'.

      Files are available for anonymous ftp; use 'guest' as the
      password.

      The data in these files represent only traffic which traverses the
      highest level of the NSFNET, not traffic within a campus or
      regional network.  Send questions/comments to nsfnet-
      [e-mail].

4. Questions About Other Networks and Internets

   4.1. We have a user who would like to access a machine on
        "EARN/BITNET".  I can't find anything on this in the domain
        name tables.  Please, what is this, and how do I connect to it?

      There are several machines on the Internet that act as gateways
      between the Internet and BITNET.  Two examples are UICVM.UIC.EDU
      and CUNYVM.CUNY.EDU.  You can address a mail message to
      [e-mail] where the message will be
      passed from the Internet to BITNET.

      Additional Information:

         These same gateways, known as INTERBIT on the BITNET/EARN side,
         transfer mail from computers on that network which support SMTP
         mail headers, onto the Internet.  (Many BITNET/EARN computers
         still do not support SMTP, which is not a part of the IBM
         protocol used, and it is not possible to send mail from those
         computers across the gateways into the Internet, in general.)




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RFC 1207        FYI Q/A - for Experienced Internet Users   February 1991


         BITNET and EARN are the two largest of several cooperating
         networks which use the IBM RSCS/NJE protocol suite, but are not
         limited to IBM systems.  These independently administered,
         interconnected networks function as a single, worldwide network
         directly connecting more than 3,300 computers in about 1,400,
         mostly higher-education, organizations worldwide.  This
         worldwide network supports electronic mail, including mailing
         lists, sender-initiated file transfer, and short "interactive"
         messages.

         BITNET, frequently used (outside of Europe) to refer to the
         whole worldwide network, technically refers to that portion in
         the United States, plus sites in other countries which are
         connected through the United States and do not have their own
         separately administered cooperating networks.  More than 550
         organizations in the U.S.  participate in BITNET.

         EARN is the European Academic Research Network.  EARN links
         more than 500 institutions in Europe and several surrounding
         countries.

         BITNET and CSNET merged organizationally on October 1, 1990, to
         form CREN, the Corporation for Research and Educational
         Networking.  The two networks remain separate at the
         operational level level, however.  (EARN and the other
         Cooperating Networks were not involved in this merger.)

5. Questions About Internet Documentation

   5.1. Where do I get information regarding ordering documents
        related to GOSIP?

      The complete information as issued by NIST is available online on
      the NIC.DDN.MIL host as PROTOCOLS:GOSIP-ORDER-INFO.TXT.  The file
      contains pointers to contact people, ordering addresses, prices,
      and, in some cases, online pathnames, for various GOSIP related
      documents.  In addition, the information as of August 1990 was
      published as an appendix to RFC 1169, "Explaining the Role of
      GOSIP" [1].

6. Questions About Domain Name System (DNS)

   6.1. Is there a DNS Query server?

      Actually, what you are looking for is the service that host
      128.218.1.109 provides on port 5555 - you simply connect to that
      host at that port, type in a fully qualified domain name and it
      responds with an internet address and closes the connection.  I



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RFC 1207        FYI Q/A - for Experienced Internet Users   February 1991


      used it when I had a host that still only had /etc/hosts and it
      did just what I needed - which was basically a manual nslookup.

      However, the vast majority of users will find it simpler to just
      use a DNS query tool and ask the DNS directly.  This doesn't
      require much sophistication, and does allow the user to see how
      short names are expanded at the user's site rather than at
      128.218.1.109 (wherever that is).  For example, suppose a user
      wants to find out the address of a fully-qualified domain name
      "X.MISKATONIC.EDU", and also see what host and address are used
      when "Z" is typed as a host name.

      Assuming the user is on a UNIX host and has a copy of the dig
      program, type:

         dig x.miskatonic.edu
      and
         dig z

         and the answers will appear.  You are now on your way to
         becoming a DNS expert.  There are other UNIX alternatives,
         e.g., nslookup, and similar programs for non-UNIX systems.
         Your local DNS guru certainly has one or more of these tools,
         and although they are often kept from the public, they are
         really quite easy to use for simple cases.

   6.2. We have been having a frequent BIND failure on both our VAX
        and Solbourne that is traced to TCP domain queries from an
        IBM NSMAIN nameserver running in cache mode (UDP queries do
        not cause this problem, though it is usually a UDP
        resolution that is active upon the crash -- this resolution
        is an innocent victim).

        I have discovered that something is trashing the hash areas
        (sometimes even as it is being recursively used in a
        resolution).  Also, occasionally the socket/file descriptor
        for the TCP connection is changed to invalid entries causing
        a reply write fail (though this is not necessarily fatal,
        and the rest of the structure is not apparently altered).

        Has any one else had frequent BIND failures (especially
        major domain sites that have heavy TCP domain loads)?

      In both the case of BIND and the IBM implementation, often called
      FAL, there are multiple versions, with older versions being truly
      bad.  Upgrade to recent version before exploring further.

      BIND has always had a problem with polluting its own database.