[dns-wg] Followup to IANA TLD delegation problem

Marcel,

Thanks for these questions. I've responded in line below to (hopefully) make 
the responses more clear.


Marcel Schneider wrote:
 > On Friday, 10 Jun 2005, Doug Barton writes:
 >
 > Dear Doug
 >
 > Thanks for responding to Jim's questions. Reading your mail
 > I still have difficulties understanding two issues:
 >
 > a) You state in [1] that after editing the root zone, VeriSign
 >    experienced an "unexpected result". What exactly was the result

As described in the first paragraph of my answers below, the wrong hostname 
appeared in a few TLD delegations. For example, if there was an existing 
hostname ns1.foo.example which pointed to 10.0.0.1, and this hostname 
appeared in the delegation of the .aa ccTLD; then a new hostname was 
introduced with the same IP address, the problem manifested itself as the 
new hostname appearing in the delegation for .aa, instead of the correct 
(old) hostname.

This error was caught by the VeriSign staff during their change management 
process for root zone changes, and brought to the attention of the IANA 
staff before that version of the zone was published. A new root zone with 
the correct changes was then published, ans verified by the ICANN and 
VeriSign staffs. Unfortunately, subsequent production of the root zone that 
should not have had changes to the delegations with the duplicate hostnames 
reflected the initial problem, and this result was not observed before the 
new zone went live. The unplanned changes to the delegations were noticed 
both by IANA staff, and at least one member of the ccTLD community, and when 
brought to VeriSign's attention, was corrected as described below.

 >    what caused it ? Whould also appreciate if you could elaborate
 >    on how VeriSign was able to fix this "unexpected result".

ICANN was not informed of the details of what caused the problem, or how it 
was fixed. We have asked VeriSign to provide us, and the community with 
additional details about this incident.

 > b) When this "unexpected result" was regarded by IANA staff as
 >    temporary and as having minimal operational impact, why was
 >    AFNIC then sent this response to their application:
 >
 > "IANA is no longer adding additional examples of host names in
 >    delegation records where multiple host names point to the same IP
 >    address".
 >
 >    The "no longer" suggests a policy change. Why did IANA not just
 >    say: "Folks we have a problem here, wait a moment until we've
 >    fixed it" ?

AFNIC had requested a clear statement about why an alternative solution was 
being discussed to fulfill their operational goals. My statement to AFNIC 
was, "Due to problems encountered in the past, we are no longer adding 
additional examples of hostnames in delegation records where multiple 
hostnames point to the same IP address." In retrospect, my statement was 
made in more absolute terms than actually intended, or needed.

I would once again like to offer my apologies for the confusion caused by 
this incident. My message to AFNIC was not intended to convey any kind of 
policy change on the part of the IANA, and I appreciate this opportunity to 
clarify the situation.

For those attending the CENTR meeting in Trondheim this week I would love to 
chat with you more in person about this, or any other issue of interest.

Warmest regards,

Doug


-- 
Doug Barton
General Manager, The Internet Assigned Numbers Authority




>>Thanks again for the opportunity to discuss these issues. I hope that the
>>group finds these answers satisfactory. We are of course happy to discuss
>>this in further detail if desired.
> 
> 
>>[1] What was the nature of the technical problem that prevented
>>multiple names in for an IP address and how was it resolved?
> 
> 
>>In November of 2004 AFNIC asked to have several hostnames added to the root
>>zone that resolved to the same IPv4 addresses as hostnames that already
>>existed. When VeriSign edited the root zone to include these new names, an
>>unexpected result occurred. In some of the TLDs that had the pre-existing
>>hostnames for these servers, the new hostnames appeared in the delegations
>>inappropriately. This problem was identified within several hours of the
>>zone going live by VeriSign staff, as well as at least one member of the
>>ccTLD community. The VeriSign and IANA staffs communicated immediately about
>>this issue, and the specific problem related to this request was fixed
>>manually by VeriSign in the next zone revision after it was identified.
> 
> 
>>Because in any pair of hostnames affected by this result the IPv4 address
>>was the same, the operational impact of this problem was minimal, if it was
>>identifiable at all.
> 
> 
> 
>>[2] Why was there no announcement that this problem existed?
> 
> 
>>The specific problem applied only to new instances of duplicate names, it
>>did not affect existing duplicate names for which no change was in process.
>>The total number of these duplicate hostnames is very small relative to the
>>rest of the zone (less than 3%), and requests to modify domains which have
>>these hostnames in their delegations are rare. There were no instances of
>>such a request from November of 2004 through March of 2005, when AFNIC
>>submitted the request for the RE ccTLD.
> 
> 
>>Because the issue affected only a small number of TLDs and name server
>>operators, IANA staff chose to address the issue with those individuals
>>directly. Often TLD managers appreciate such specific cases being dealt with
>>on a personal level.
> 
> 
> 
>>[3] Are safeguards now in place to prevent this sort of problem recurring?
> 
> 
>>Yes. VeriSign has informed us that the general problem which produced the
>>original unexpected result has now been corrected. Additionally, IANA staff
>>have enhanced efforts to monitor the "live" root zone from several different
>>servers, and use that data to proactively monitor the results of change
>>requests.
> 
> 
> 
>>[4] What procedures does IANA (or ICANN?) have to make sure that changes
>>to the TLD delegation process or problems with that process are properly
>>communicated to its stakeholders?
> 
> 
>>The procedure that IANA uses to communicate changes in the TLD delegation
>>process follows the typical ICANN formula of involving key stakeholders at
>>early stages, opening proposals up for public comment, incorporating
>>appropriate comments into the final version, and posting the procedure for
>>its stakeholders. A relevant example of this process is the "Delegation Data
>>Procedure," which is posted at
>>http://www.iana.org/procedures/delegation-data.html.
> 
> 
>>Specific problems in the root management process are evaluated on a case by
>>case basis. When necessary, there is a mailing list composed of the contact
>>addresses for each of the TLD managers that can be utilized for any issue of
>>wide interest to the TLD manager community. As noted above, cases which
>>affect one, or a few TLDs are often dealt with on a one-to-one basis, with
>>the appreciation of the relevant TLD manager(s).
> 
> 
> 
>>[5] Were those procedures followed for this incident? If not, why not?
> 
> 
>>The procedure for communicating changes to the TLD delegation process was
>>not followed in this specific case because there was no formal change of
>>process.
> 
> 
>>The specific problem which produced the delay in processing AFNIC's request
>>for RE was always understood to be temporary. As discussed above, rather
>>than widely disseminate the information about this issue to the TLD manager
>>community, IANA staff chose to communicate directly with those affected by
>>the issue.
> 
> 
> 
>>ICANN's goal, as always, is to cooperate with the TLD managers in
>>implementing the changes they feel are appropriate for their TLDs, while
>>also maintaining the stability of the DNS. We regret if our cautious
>>handling of this particular request, or the timing of our responses to the
>>group's reasonable questions, has caused any undue confusion in the DNS
>>community about ICANN's dedication to that goal. We welcome comment and
>>discussion on these topics.
> 
> 
>>I am enclosing below some information about the current (at this writing,
>>2005061000) root zone that may be relevant to this discussion. The first
>>part is the complete list of IPv4 addresses that have multiple hostnames
>>associated. There are no IPv6 addresses with multiple hostnames. The second
>>part is a compilation of statistics about the current zone.
> 
> 
>>Regards,
> 
> 
>>Doug
> 
> 
> 
>>128.112.129.15:	dns.princeton.edu c.ext.nic.fr
>>192.134.0.49:	c.nic.fr ns3.nic.fr
>>192.36.144.116:	slave.sth.netnod.se slave1.sth.netnod.se
>>192.93.0.1:	a.nic.fr ns1.nic.fr
>>192.93.0.4:	b.nic.fr ns2.nic.fr
>>193.176.144.6:	e.ext.nic.fr ns3.domain-registry.nl
>>193.51.208.13:	dns.inria.fr a.ext.nic.fr
>>204.152.184.64:	ns-ext.vix.com ns-ext.isc.org
>>204.74.112.1:	tld1.basicfusion.net tld1.ultradns.net ud1.ns.net.ua
>>204.74.113.1:	tld2.basicfusion.net tld2.ultradns.net
> 
> 
>>Statistics
>>==========
>>Number of gTLDs:                 15
>>Number of ccTLDs:               245
>>Total number of TLDs:           260
> 
> 
>>Number of IPv4 hosts:           798
>>Number of IPv4 addresses:       798
> 
> 
>>Number of IPv6 hosts:            40
>>Number of IPv6 addresses:        41
>>TLDs with IPv6 glue:             50
> 
> 
>>Total TLD name server hosts:    797
> 
> 
> 
>>-- 
>>Doug Barton
>>General Manager, The Internet Assigned Numbers Authority