RFC 1207
FYI on Questions and Answers: Answers to commonly asked "experienced Internet user" questions
FYI on Questions and Answers 💖
Answers to Commonly asked "Experienced Internet User" Questions
- RFC 1207 (FYI 7), dated February 1991 ✨
- Series: Network Working Group 🌐
- Authors: G. Malkin (FTP Software, Inc.), A. Marine (SRI), and J. Reynolds (ISI) 👯
- Category: FYI, which is informational. It doesn't specify any standard 🙅
- Obsoletes or updates: the title block doesn't list either one 🦋
Status of this Memo 🎀
Okay so this FYI RFC is one of two FYIs called "Questions and Answers" (Q/A), made by the User Services Working Group of the Internet Engineering Task Force (IETF) 🌈 The goal is to write down the most commonly asked questions and answers on the Internet. It's giving FAQ era 💅
This memo is info for the Internet community. It doesn't set any standard, and you can distribute it as much as you want 🦋
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........................................... 151. Introduction ✨
A few months back, some people kept an eye on several major mailing lists and pulled out the questions that were important or came up a lot. This FYI is one of two in a series that present those questions and their answers. The first one, FYI 4, covered questions that new Internet users commonly ask 🫶
The goal is to codify the Internet lore so network operations staff, especially those whose networks are just joining the Internet, have an accurate and up-to-date set of references to work from 📚 Also, the repeats get moved off the mailing lists, so subscribers don't have to read the same questions and answers over and over. Main character energy for the lists 😭
The questions are loosely grouped by topic so they're easy to read. Each one shows the question first, then the answer (or answers) as it appeared on the list 💅
Sometimes answers get trimmed to save space. If a question wasn't answered on the list, the editors wrote an answer, and those aren't marked any differently from the list answers. Sometimes the editors add extra info to make things more complete, and that goes under a heading called "Additional Information" 🔥
The answers are as correct as the reviewers could make them. But a lot of this info changes over time, so as the FYI gets updated, time-related errors will get fixed 🌸
Lots of the questions are in first person, and the answers were written to whoever asked. Those phrasings stay the same unless something needed changing for clarity. The correspondents' names were removed 🙈
The Q/A mailing lists are maintained by Gary Malkin at FTP.COM. A subgroup of the User Services Working Group uses them to discuss the Q/A FYIs. They include:
quail@ftp.com: the discussion list, mainly used for pre-release review of the Q/A FYIs.quail-request@ftp.com: how you join the quail mailing list.quail-box@ftp.com: where questions and answers get forwarded and stored. You don't have to be on quail to forward to quail-box 🎀
2. Acknowledgments 🫶
Huge thanks to everyone who helped out and contributed 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 keeps a bunch of stats at nis.nsf.net (35.1.1.48) in the stats directory. The info includes packet counts by NSS and byte counts by type of use (ftp, smtp, telnet, etc.). The filenames look like NSFyy-mm.type.
The files are available for anonymous ftp, and you use guest as the password 🔑
The data only covers traffic that goes across the highest level of NSFNET. It doesn't include traffic inside a campus or a regional network. If you have questions or comments, send them to nsfnet-info@merit.edu 💌
4. Questions About Other Networks and Internets 🧚
4.1. A user wants to reach a machine on "EARN/BITNET" 🧚
Okay bestie, so someone has a user who wants to access a machine on "EARN/BITNET," but it's nowhere in the domain name tables. Like, what even is it, and how do you connect to it? 🤔
There are a few machines on the Internet acting as gateways between the Internet and BITNET, like UICVM.UIC.EDU and CUNYVM.CUNY.EDU. You can address a mail message to user%nodename.bitnet@uicvm.uic.edu, and it gets passed from the Internet over to BITNET ✨
Additional Information:
The same gateways, called INTERBIT on the BITNET/EARN side, move mail from computers on that network that support SMTP mail headers onto the Internet. Lots of BITNET/EARN computers still don't support SMTP, since it isn't part of the IBM protocol they use. So in general, you can't send mail from those computers through the gateways onto the Internet 💀
BITNET and EARN are the two biggest of several cooperating networks that use the IBM RSCS/NJE protocol suite, but they aren't limited to IBM systems. These independently administered networks are interconnected and work as one worldwide network, directly connecting more than 3,300 computers at about 1,400 organizations around the world, mostly higher-education ones. The network supports email (including mailing lists), sender-initiated file transfer, and short "interactive" messages 🌐
Outside of Europe, people often say "BITNET" to mean the whole worldwide network. Technically, though, it means the portion in the United States, plus sites in other countries that connect through the United States and don't have their own separately administered cooperating networks. More than 550 organizations in the U.S. take part in BITNET 🇺🇸
EARN is the European Academic Research Network, and it 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. They're still separate at the operational level, though. (EARN and the other Cooperating Networks weren't involved in this merger.) 🤝
5. Questions About Internet Documentation 📚
5.1. Where do I get information regarding ordering documents related to GOSIP? 🛒
The complete info NIST issued is online on the NIC.DDN.MIL host as PROTOCOLS:GOSIP-ORDER-INFO.TXT. The file has pointers to contact people, ordering addresses, prices, and, in some cases, online pathnames for different GOSIP-related documents. Also, the info 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?
Okay so, what you're actually looking for is the service that host 128.218.1.109 runs on port 5555. You just connect to that host on that port, type in a fully qualified domain name, and it sends back an internet address and closes the connection 🦋. I used it when I had a host that still only had /etc/hosts, and it did exactly what I needed, which was basically a manual nslookup 💅.
Honestly though, most people will be happier just using a DNS query tool and asking the DNS directly 💖. It doesn't take much skill, and it lets you see how short names get expanded on your site instead of over at 128.218.1.109 (wherever that is 👀). Say you want the address for the fully-qualified name X.MISKATONIC.EDU, and you also want to see which host and address get used when you type Z as a host name.
If you're on a UNIX host with a copy of the dig program, type:
dig x.miskatonic.edu
and
dig zand the answers will pop up 🎀. Congrats, you're on your way to becoming a DNS expert ✨. There are other UNIX options, like nslookup, plus similar programs for non-UNIX systems. Your local DNS guru definitely has one or more of these tools 🧚. They're often kept on the down-low, but they're really easy to use for simple stuff 🫶.
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).
This one is giving chaos 😭. The writer has figured out that something is trashing the hash areas, sometimes even while they're being used in the middle of a resolution 💀. Also, every so often the socket/file descriptor for the TCP connection gets switched to invalid entries, which causes a reply write to fail. That isn't necessarily fatal, and the rest of the structure doesn't look messed up 🙈.
They're asking if anyone else has had frequent BIND failures, especially big domain sites with heavy TCP domain loads 🔥.
Here's the tea. For both BIND and the IBM implementation (often called FAL), there are multiple versions, and the older ones are truly bad 😬. Upgrade to a recent version before you go digging any further ✨.
BIND has always had a problem with polluting its own database 💅.
These problems have been tied to TCP connections, NS RRs with small TTLs, and a few other causes 🌈. The vibe in the community is that bug fixing has often just reduced the problem by 90% instead of actually eliminating it 🙃.
IBM's DNS support (outside of UNIX systems) is interesting in its techniques and encouraging in how it's improving 🌸. It's still a little depressing next to most other DNS software, though 😭. IBM also uses terminology that's a bit different from usual DNS, and it keeps some archaic syntax, like .. 💀.
The combo of an old BIND and an old IBM server is just plain unpleasant 🫠.
6.3. Is the model used by the domain name system for host names that the owner of a name gets to choose its case?
The DNS model works like this: you control your name at a specific point in the name space, so you're free to pick whatever case you want, until you reach points where you hand control over to someone else 💜. In practice though, several implementations don't do the right thing 😤. IBM implementations often squish everything into a single case 🙈.
6.4. According to RFC 1034 [2], section 4.2.1, one should not have to code glue RR's for name server's names unless they are below the cut. When I don't put glue RR's in, and do a query for NS records, the "additional" field is left blank. As far as I can tell, all other zones I query for NS records have this filled with the IP addresses of the NS hosts. Is this required or should I not be concerned that the additional field is empty?
Good news bestie, the protocol says an empty additional field is not a problem when the name server's name is not "below" the cut 🎀.
In practice though, putting glue in where it isn't needed can cause problems when the servers named in the glue are used for several zones 😬. That's broken behavior in BIND. Leaving glue out can also cause its own problems in BIND, usually when the server name is hard to resolve 💀. So the bottom line: only put glue in when it's required, and don't get fancy with aliases or anything else tricky when identifying name servers 🫶.
7. Questions About Network Management Implementations 🦋
7.1. In reading the SNMP RFCs [3,4,5,6] I find mention of authentication of PDUs. Are there any standards for authentication mechanisms?
There's an IETF working group on exactly this problem 👑. They're close to a solution, but nothing has made it to RFC publication yet 😩. Expect something solid and implementable by October of 1991 ⭐.
7.2. Can vendors make their enterprise-specific variables available to users through a standard distribution mechanism?
Yes! 💖 But before someone submits a MIB, they should check it out themselves first 🧐.
On uu.psi.com in pilot/snmp-wg/, there are two files:
mosy-sparc-4.0.3.c
mosy-sun3-3.5The first one runs on a Sun-Sparc and the second one runs on a Sun-3 🌈. After you grab one of these files in BINARY mode over anonymous FTP, the submitter can run their MIB through it, like this:
% mosy mymib.myOnce your MIB passes, send it to:
mib-checker@isi.eduIf everything checks out, the mib-checker will get it installed in the /share/ftp/mib directory on venera.isi.edu 🎉.
Heads up: this processing does not offer an official endorsement 🫣. Also, the documents submitted must not be marked proprietary, confidential, or the like.
7.3. I have a question regarding those pesky octet strings again. I use the variable-type field of the Response pdu to determine how the result should be displayed to the user. For example, I convert NetworkAddresses to their dotted decimal format ("132.243.50.4"). I convert Object Identifiers into strings ("1.3.6.1.2....").
I would LIKE to just print Octet Strings as strings 🙏. But this causes a problem with things like atPhysAddress, where the Octet string holds the 6 byte address instead of a printable ASCII string 😵. In that case, I'd want to display the 6 bytes instead of trying to print the string.
MY QUESTION IS: Does anyone have a suggestion for how I can tell whether I can just print the string or whether I should display the octet bytes? * Remember: I want to support enterprise specific variables too 💅.
In general, there's no way to tell what's inside an OCTET STRING without knowing something about the object it came from 🫠. In MIB-II [6], some objects are marked as DisplayString, which has the syntax of OCTET STRING but is restricted to characters from the NVT ASCII character set (see the TELNET Specification, RFC 854 [7], for more info). These objects are:
sysDescr
sysContact
sysName
sysLocation
ifDescrIf you want to decide how to display strings arbitrarily, without knowing anything about the object, you can scan the octets looking for any octet that isn't printable ASCII 🔍. If you find at least one, print the entire string octet by octet in "%02x:" notation 🌸. If all the octets are printable ASCII, you can just printf the string ✨.
7.4. If archived MIBs must be 1155-compatible [3], it would be nice if those who submit them check them first. Where are these MIB tools available for public FTP? Ideally, a simple syntax checker (that didn't actually generate code) would be nice.
The ISODE 6.0 release has a tool called MOSY 🧚. It recognizes the 1155 syntax and produces a flat ASCII file. If you can run your MIB through MOSY without problems, then you're OK 💜.
7.5. Suppose I want to create a private MIB object for causing some action to happen, say, do a reset. Should the syntax of this object specify a value such as:
Syntax:
INTEGER {
perform reset (1),
}even though there is only a single value? Or, is it ok to just allow a Set on this object with any value to perform the desired action? If the later, how is this specified?
For our SNMP manageable gizmos and doohickies with similar "action" type MIB variables, I've defined two values:
Syntax:
INTEGER {
reset(1)
not-reset(2)
}I also defined behavior so that the only valid value the variable can be set to is "reset" (which gets returned in the get response PDU). At all other times, a get/getnext will respond with "not-reset" 🦋✨.
8. Questions about Serial Line Internet Protocol (SLIP) and Point-to-Point Protocol (PPP) Implementations ✨
8.1. Is SLIP really only for synchronous serial lines? 🤔
okay so someone heard that SLIP [8] only runs on synchronous serial lines. Is that true? And is there something about SLIP that stops it from being used on async lines? 🧐
Other way around, bestie 💅 SLIP is designed for async lines and is not a good fit on sync lines. PPP [9, 10] works on either one, so if you're building something new, PPP is what you should be implementing 🫶
8.2. Where can I find PPP info, and can it be used outside the Internet? 📚
Someone who's very into standards in this area wants to know where to find more on PPP. They're also asking whether it could work in other fields, like telecontrol and telemetering, where there are tons of proprietary, incompatible, and hard-to-maintain point-to-point protocols 😩
PPP was designed to be useful for many protocols besides just IP 🌈 Whether it'd work for your specific application should probably be discussed with the IETF's Point-to-Point Protocol Working Group discussion list. For general discussion, the address is ietf-ppp@ucdavis.edu. To subscribe, use ietf-ppp-request@ucdavis.edu. The PPP specification is available as RFC 1171 [9], and a PPP options specification is available as RFC 1172 [10].
In UnixWorld of April 1990 (Vol. VII, No. 4, Pg. 85), Howard Baldwin wrote this 📰
"Point-to-Point Protocol (PPP) has just been submitted to the CCITT from the Internet Engineering Task Force. It specifies a standard for encapsulating Internet Protocol data and other network layer (level three on ISO's OSI Model) protocol information over point-to-point links; it also provides ways to test and configure lines and the upper level protocols on the OSI Model. The only requirement is a provision of a duplex circuit either dedicated or switched, that can operate in either an asynchronous or synchronous mode, transparent to the data-linklayer frame. "According to Michael Ballard, director of network systems for Telebit, PPP is a direct improvement upon Serial Line Internet Protocol (SLIP), which had neither error correction nor a way to exchange network address."
8.3. Can I run SLIP on an IBM with SCO Xenix/Unix and a multi-port serial board? 🖥️
Is there a way to run a SLIP program on an IBM computer running SCO Xenix/Unix with a multi-port serial board? Let's find out 👀
SCO TCP/IP for Xenix supports SLIP, and it works ✅ But be warned, bestie 🚨 SCO SLIP works only with SCO serial drivers, so it will not work with intelligent boards that come with their own drivers. If you want lots of SLIP ports, you'll need lots of dumb ports, maybe with a multi-dumb-port board 🙈
Here's the setup that got messy. It's SunOS 3.5, with the 4.3BSD TCP, IP & SLIP distributions installed. SLIP is running between the "ttya" ports of two Sun 3/60's. ping, rlogin, etc. work fine, but an NFS mount results in server not responding: RPC Timed Out 😭
SunOS 3.5 turns the UDP checksum off, which is legal and works okay over interfaces such as ethernet, which has link-level checksumming 🧠 On the other hand, SLIP doesn't perform checksums, so running NFS over SLIP requires you to turn the UDP checksum on. Otherwise, you'll experience erratic behavior like the one described above 💀
Save the older kernel and try this to patch up the kernel:
% adb -k -w /vmunix /dev/kmem udpcksum?w 19. Questions About Routing 🗺️
9.1. Where can I read about "maximum entropy routing"? 🧩
Some posts mentioned "maximum entropy routing." Could someone point me to on-line or off-line references on this topic? 🥺
Try NYU CSD Technical Report 371: "Some Comments on Highly Dynamic Network Routing," by Herbert J. Bernstein, May 1988 📖
10. Other Protocol and Standards Implementation Questions 🧁
10.1. What is Ethernet type "80F3"? 👀
Does anyone recognize ethernet type "80F3"? It's not in RFC 1010, but it's showing up on the net 🤨
Ethernet type 0x80F3 is used by AppleTalk for address resolution. You must have Macs on your network that are directly connected to Ethernet 🍎 These packets are used by the Mac (generally at startup) to determine a valid AppleTalk node number.
Additional information: RFC 1010 is obsolete. Please consult RFC 1060 [11], the current "Assigned Numbers" (issued March 1990), which does list "80F3":
Ethernet Exp. Ethernet Description References
------------- ------------- ----------- ----------
decimal Hex decimal octal
33011 80F3 - - AppleTalk AARP (Kinetics)[XEROX]10.2. Why is "Bad proto" so high in netstat? 📈
Does anyone know what a high value for "Bad proto" means in netstat output on Unix machines using ethernet? 😳 They're seeing values in the tens of thousands out of a few hundred thousand packets sent and received in total. Some "Bad proto" values are negative, too. (Off the scale?) Any help would be appreciated 🙏
This probably means you're getting tens of thousands of broadcast packets from some host or hosts on your network 📡 You might want to buy or rent a LAN monitor, or install one of the public-domain packages to see which private protocol is guilty 🕵️ "FYI on a Network Management Tool Catalog: Tools for Monitoring and Debugging TCP/IP Internets and Interconnected Devices" (RFC 1147, FYI 2), [12] has pointers to tools that may help you zero in on the problem.
10.3. How do I configure broadcast addresses with subnets? 📡
Which RFC explains the proper way to configure broadcast addresses when using subnets?
Consult RFC 1122, "Requirements for Internet Hosts -- Communication Layer" [13] 🫶
10.4. What are .TAR files? 📦
Can anyone tell me what .TAR files actually are? Are they like ZIP or LZH for the IBM PC's? If so, how do I get a compressor/decompressor for .TAR files, and what computer does this run on? 🤷♀️
TAR stands for "Tape ARchive" 🎀 It's a Unix utility that takes files, and directories of files, and creates a single large file. It was originally meant to back up directory trees onto tape (hence the name), but TAR is also used to combine files for easier electronic file transfer 💜
11. Suggested Reading 📚🌸
For further information about the Internet and its protocols in general, you may choose to obtain copies of the following works 🦋
Bowers, K., T. LaQuey, J. Reynolds, K. Roubicek, M. Stahl, and A. Yuan, "Where to Start - A Bibliography of General Internetworking Information", RFC 1175, FYI 3, CNRI, U Texas, ISI, BBN, SRI, Mitre, August 1990.
Braden, R., Editor, "Requirements for Internet Hosts -- Communication Layer", RFC 1122, Internet Engineering Task Force, October 1989.
Braden, R., Editor, "Requirements for Internet Hosts -- Application and Support", RFC 1123, Internet Engineering Task Force, October 1989.
Comer, D., "Internetworking with TCP/IP: Principles, Protocols, and Architecture", Prentice Hall, New Jersey, 1989.
Frey, D. and R. Adams, "!%@:: A Directory of Electronic Mail Addressing and Networks", O'Reilly and Associates, Newton, MA, August 1989.
Krol, E., "The Hitchhikers Guide to the Internet", RFC 1118, University of Illinois Urbana, September 1989.
LaQuey, T, Editor, "Users' Directory of Computer Networks", Digital Press, Bedford, MA, 1990.
Malkin, G., and A. Marine, "FYI on Questions and Answers - Answers to Commonly asked "New Internet User" Questions", RFC 1206, FYI 4, FTP Software, Inc., SRI, February 1991.
Postel, J., Editor, "IAB Official Protocol Standards", RFC 1140, Internet Activities Board, May 1990.
Quarterman, J., "Matrix: Computer Networks and Conferencing Systems Worldwide", Digital Press, Bedford, MA, 1989.
Reynolds, J., and J. Postel, "Assigned Numbers", RFC 1060, USC/Information Sciences Institute, March 1990.
Socolofsky, T., and C. Kale, "A TCP/IP Tutorial", RFC 1180, Spider Systems Limited, January 1991.
Stevens, W., "UNIX Network Programming", ISBN 0-13-949876-1, Prentice Hall, Englewood Cliffs, NJ, 1990.
Stine, R., Editor, "FYI on a Network Management Tool Catalog: Tools for Monitoring and Debugging TCP/IP Internets and Interconnected Devices" RFC 1147, FYI 2, Sparta, Inc., April 1990.
12. References 📑
[1] Cerf, V., and K. Mills, "Explaining the Role of GOSIP", RFC 1169, IAB, NIST, August 1990.
[2] Mockapetris, P., "Domain Names - Concepts and Facilities", RFC 1034, USC/Information Sciences Institute, November 1987.
[3] Rose, M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", RFC 1155, Performance Systems International, Hughes LAN Systems, May 1990.
[4] McCloghrie, K., and M. Rose, "Management Information Base for Network Management of TCP/IP-based internets", RFC 1156, Hughes LAN Systems, Performance Systems International, May 1990.
[5] Case, J., M. Fedor, M. Schoffstall, and J. Davin, "A Simple Network Management Protocol (SNMP)", RFC 1157, SNMP Research, Performance Systems International, Performance Systems International, MIT Laboratory for Computer Science, May 1990.
[6] Rose, M., Editor, "Management Information Base for Network Management of TCP/IP-based internets: MIB-II", RFC 1158, Performance Systems International, May 1990.
[7] Postel, J., and J. Reynolds, "TELNET Protocol Specification", RFC 854, USC/Information Sciences Institute, May 1983.
[8] Romkey, J., "A Nonstandard for Transmission of IP Datagrams over Serial Lines: SLIP", RFC 1055, June 1988.
[9] Perkins, D., "The Point-to-Point Protocol: A Proposal for Multi-Protocol Transmission of Datagrams Over Point-to-Point Links", RFC 1171, CMU, July 1990.
[10] Perkins, D., and R. Hobby, "The Point-to-Point Protocol (PPP) Initial Configuration Options", CMU, UC Davis, July 1990.
[11] Reynolds, J., and J. Postel, "Assigned Numbers", RFC 1060, USC/Information Sciences Institute, March 1990.
[12] Stine, R., Editor, "FYI on a Network Management Tool Catalog: Tools for Monitoring and Debugging TCP/IP Internets and Interconnected Devices" RFC 1147, FYI 2, Sparta, Inc., April 1990.
[13] Braden, R., Editor, "Requirements for Internet Hosts -- Communication Layer", RFC 1122, Internet Engineering Task Force, October 1989.
13. Security Considerations 🔐
Security issues are not discussed in this memo.
14. Authors' Addresses 💌
Gary Scott Malkin
FTP Software, Inc.
26 Princess Street
Wakefield, MA 01880
Phone: (617) 246-0900
EMail: gmalkin@ftp.com
April N. Marine
SRI International
Network Information Systems Center
333 Ravenswood Avenue, EJ294
Menlo Park, CA 94025
Phone: (415) 859-5318
EMail: APRIL@nic.ddn.mil
Joyce K. Reynolds
USC/Information Sciences Institute
4676 Admiralty Way
Marina del Rey, CA 90292-6695
Phone: (213) 822-1511
EMail: jkrey@isi.eduThat's the whole RFC, bestie! 🌈✨ You made it to the end 🫶💖
📦 where this page comes from
- ietf: rfc1207 1991-02
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms