summaryrefslogtreecommitdiff
path: root/doc/draft/draft-ietf-dnsext-dnsmib-historical-00.txt
diff options
context:
space:
mode:
Diffstat (limited to 'doc/draft/draft-ietf-dnsext-dnsmib-historical-00.txt')
-rw-r--r--doc/draft/draft-ietf-dnsext-dnsmib-historical-00.txt226
1 files changed, 226 insertions, 0 deletions
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]