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diff --git a/doc/draft/draft-ietf-dnsext-dnsmib-historical-00.txt b/doc/draft/draft-ietf-dnsext-dnsmib-historical-00.txt new file mode 100644 index 00000000..f8dbb52e --- /dev/null +++ b/doc/draft/draft-ietf-dnsext-dnsmib-historical-00.txt @@ -0,0 +1,226 @@ + + + + + + +Network Working Group R. Austein +draft-ietf-dnsext-dnsmib-historical-00.txt InterNetShare.com, Inc. + October 2000 + + + Applicability Statement for DNS MIB Extensions + + +Status of this document + + This document is an Internet-Draft and is in full conformance with + all provisions of Section 10 of RFC 2026. + + 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 progress." + + The list of current Internet-Drafts can be accessed at + <http://www.ietf.org/ietf/1id-abstracts.txt> + + The list of Internet-Draft Shadow Directories can be accessed at + <http://www.ietf.org/shadow.html> + + Distribution of this document is unlimited. Please send comments to + the Namedroppers mailing list <namedroppers@ops.ietf.org>. + +Abstract + + More than six years after the DNS Server and Resolver MIB extensions + became proposed standards, there still has not been any significant + deployment of these MIB extensions. This note examines the reasons + why these MIB extensions were never deployed, and recommends retiring + these MIB extensions by moving them to Historical status. + +History + + The road to the DNS MIB extensions was paved with good intentions. + + In retrospect, it's obvious that the working group never had much + agreement on what belonged in the MIB extensions, just that we should + have some. This happened during the height of the craze for MIB + extensions in virtually every protocol that the IETF was working on + + + +Austein Expires 2 May 2001 [Page 1] + +draft-ietf-dnsext-dnsmib-historical-00.txt October 2000 + + + at the time, so the question of why we were doing this in the first + place never got a lot of scrutiny. Very late in the development + cycle we discovered that much of the support for writing the MIB + extensions in the first place had come from people who wanted to use + SNMP SET operations to update DNS zones on the fly. Examination of + the security model involved, however, led us to conclude that this + was not a good way to do dynamic update and that a separate DNS + Dynamic Update protocol would be necessary. + + The MIB extensions started out being fairly specific to one + particular DNS implementation (BIND-4.8.3); as work progressed, the + BIND-specific portions were rewritten to be as implementation-neutral + as we knew how to make them, but somehow every revision of the MIB + extensions managed to accrete new counters that just happened to + closely match statistics kept by some version of BIND. As a result, + the MIB extensions ended up being much too big, which raised a number + of concerns with the network management directorate, but the WG + resisted every attempt to remove any of these variables. In the end, + large portions of the MIB extensions were moved into optional groups + in an attempt to get the required subset down to a manageable size. + + The DNS Server and Resolver MIB extensions were one of the first + attempts to write MIB extensions for a protocol usually considered to + be at the application layer. Fairly early on it became clear that, + while it was certainly possible to write MIB extensions for DNS, the + SMI was not really designed with this sort of thing in mind. A case + in point was the attempt to provide direct indexing into the caches + in the resolver MIB extensions: while arguably the only sane way to + do this for a large cache, this required much more complex indexing + clauses than is usual, and ended up running into known length limits + for object identifiers in some SNMP implementations. + + Furthermore, the lack of either real proxy MIB support in SNMP + managers or a standard subagent protocol meant that there was no + reasonable way to implement the MIB extensions in the dominant + implementation (BIND). When the AgentX subagent protocol was + developed a few years later, we initially hoped that this would + finally clear the way for an implementation of the DNS MIB + extensions, but by the time AgentX was a viable protocol it had + become clear that nobody really wanted to implement these MIB + extensions. + + Finally, the MIB extensions took much too long to produce. In + retrospect, this should have been a clear warning sigh, particularly + when the WG had clearly become so tired of the project that the + authors found it impossible to elicit any comments whatsoever on the + documents. + + + + +Austein Expires 2 May 2001 [Page 2] + +draft-ietf-dnsext-dnsmib-historical-00.txt October 2000 + + +Lessons + + Observations based on the preceding list of mistakes, for the benefit + of anyone else who ever attempts to write DNS MIB extensions again: + + - Define a clear set of goals before writing any MIB extensions. + Know who the constituency is and make sure that what you write + solves their problem. + + - Keep the MIB extensions short, and don't add variables just because + somebody in the WG thinks they'd be a cool thing to measure. + + - If some portion of the task seems to be very hard to do within the + SMI, that's a strong hint that SNMP is not the right tool for + whatever it is that you're trying to do. + + - If the entire project is taking too long, perhaps that's a hint + too. + + +Recommendation + + In view of the community's apparent total lack of interest in + deploying these MIB extensions, we recommend that RFCs 1611 and 1612 + be reclassified as Historical documents. + +Security Considerations + + Getting rid of the DNS MIB extensions undoubtedly closes a few + security holes, or would if anybody had ever implemented them. + +IANA Considerations + + Getting rid of the DNS MIB extensions should not impose any new work + on IANA. + +Acknowledgments + + The author would like to thank all the people who were involved in + this silly project over the years for their optimism and patience, + misguided though it may have been. + +References + + [DNS-SERVER-MIB] Austein, R., and Saperia, J., "DNS Server MIB + Extensions", RFC 1611, May 1994. + + + + + +Austein Expires 2 May 2001 [Page 3] + +draft-ietf-dnsext-dnsmib-historical-00.txt October 2000 + + + [DNS-RESOLVER-MIB] Austein, R., and Saperia, J., "DNS Resolver MIB + Extensions", RFC 1612, May 1994. + + [DNS-DYNAMIC-UPDATE] Vixie, P., Ed., Thomson, S., Rekhter, Y., and + Bound, J., "Dynamic Updates in the Domain Name System (DNS + UPDATE)", RFC 2136, April 1997. + + [AGENTX] Daniele, M., Wijnen, B., Ellison, M., and Francisco, D., + "Agent Extensibility (AgentX) Protocol Version 1", RFC 2741, + January 2000. + +Author's addresses: + + Rob Austein + InterNetShare.com, Inc. + 505 West Olive Ave., Suite 321 + Sunnyvale, CA 94086 + USA + sra@hactrn.net + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Austein Expires 2 May 2001 [Page 4] |