- dns-wg - mailman.ripe.net

AAAA lookup misbehaviour
by David Malone 02 Jul '04

02 Jul '04

At the last RIPE meeting I was given an action item: Write up a draft RIPE document summarizing the observations made regarding AAAA resolution problems. Circulate to the list, initiate discussion what to, i.e. whom to approach with the list of errors/problems seen. I checked with Peter, and he says the documents are pretty freeform, so I've written a few paragraphs, included below. David This document is a short description of problems with certain DNS systems that have come to light with the deployment of IPv6 enabled software. --- One of the services that DNS provides is a facility for mapping host names to IPv4 addresses. This is probably the most common used service that DNS provides, and is achieved requesting a record of type "A" for the host name. Records of type A can only store an IPv4 address, and so with the introduction of IPv6, a new record type, AAAA has been introduced. It is becoming increasingly common for software to first issue a request of type AAAA, and if no record of that type is found then to issue a request for a record of type A. A request for a record of type AAAA causes no problems for most DNS servers, however some DNS servers have been found that have problems answering queries not of type A. The technical details of these problems are explained in the IETF draft document draft-ietf-dnsop-misbehavior-against-aaaa-01.txt. In 2004, about 0.5--1% of name servers seem to have to have a problem of this nature. The end result of these issues is that connecting to a site using a problematic name server may be impossible, intermittent or significantly delayed. To prevent introducing more DNS servers with such issues, testing of new DNS equipment should include checking that the response for records is in accordance with the RFCs. As DNS load balancing software has often fallen foul of these problems, particular care should be taken in testing and validating such systems. The fact that problematic nameservers exist is in itself a problem. Where these issues cause direct inconvenience, the maintainers of the server and the maintainers of the DNS data should be notified to allow a normal service to be restored. However, often it is difficult for end users to identify the source of these problems, (for example, where an image embedded in a web page being served from a host with a problem hostname). It is also possible to automatically produce lists of names and nameservers that exhibit these problems. Clearly it is possible to automatically mail hostmaters or to publish "hall of shame" lists based on such data. It is unclear if such actions would achieve any useful effect, as service maintainers are usually primarily concerned about complaints directly from paying users!

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Re: [dns-wg] IANA proposal for changing TLD delegations
by Marcel Schneider 28 Jun '04

28 Jun '04

On Thursday, 24 Jun 2004, Jim Reid writes: > IANA has published a proposal on how it plans to deal with changes in > the root zone for TLD delegations. It's at > http://www.iana.org/procedures/delegation-data.html. > I would recommend that people read this and comment on it. TLD owners > in particular might want to pay special attention to the part headed > "IANA Procedures for Removing Problematic Delegation Data ". We have been checking the document before and found nothing to worry about. The part you are referring to deals with restoring the DNS in case of emergency. The title is of course not well chosen - it could be interpreted in different ways, as suggested by Jim, but the measures are sound. Marcel

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Re: [dns-wg] IANA proposal for changing TLD delegations
by Jim Reid 24 Jun '04

24 Jun '04

>>>>> "Brad" == Brad Knowles <brad.knowles(a)skynet.be> writes: >> http://www.iana.org/procedures/delegation-data.html. Brad> I read the proposal on the web page. Except for their Brad> complete lack of discussion of things like IPv6, DNSSEC, Brad> etc..., I don't see anything specifically and obviously Brad> wrong with what they've got. Everything seems, more or Brad> less, fairly reasonable. Brad> Do you have some specific comments/views on the Brad> proposal? If so, could/would you be willing to share them Brad> with us? Well the section "IANA Procedures for Removing Problematic Delegation Data" suggests to me that IANA may unilaterally decide to change the delegation of a TLD without the consent of the TLD operator. And it's not at all clear what circumstances and criteria would prevail for IANA to justify taking that action. Not that this practice can ever be justified IMO. IANA can't possibly know what the best or correct name servers for some TLD will be. By definition only the TLD operator can decide that. I'm rather surprised that nobody seems to think this is part of the proposal could be more than a little controversial. And if IANA starts changing the root zone whenever it feels like doing so -- OK I exaggerate for effect -- that sets a very dangerous precedent. When it comes to the root zone, IANA must only act as the registry. It must always be someone/something else that decides what goes in the root zone. Of course this doesn't preclude IANA from checking delegations and making recommendations about changes. But there must be a seperate role that has the responsibility of instructing IANA to make changes to the root zone. IANA must not have that authority itself. Perhaps this section of the proposal is just badly written? However I fear it's badly thought out instead.

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IANA proposal for changing TLD delegations
by Jim Reid 24 Jun '04

24 Jun '04

IANA has published a proposal on how it plans to deal with changes in the root zone for TLD delegations. It's at http://www.iana.org/procedures/delegation-data.html. I would recommend that people read this and comment on it. TLD owners in particular might want to pay special attention to the part headed "IANA Procedures for Removing Problematic Delegation Data ". Unfortunately the closing date for comments was June 21st -- I've only just seen this document. However a revised version is promised for June 28th, so there may still be an opportunity to comment on the current one.

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Re: [dns-wg] Re: [address-policy-wg] Policy Change Request - Allow address allocations for anycast DNS operation
by Jim Reid 16 Jun '04

16 Jun '04

Not having seen the whole discussion thread, it's a bit hard to make sense of what's been said. However it appears to be that someone is saying that the need for anycasting (and more specifically special address allocations for anycast name servers) can be discounted if ENDS0 was more widely used. This is a flawed argument IMO. As Peter has said, resolvers that aren't EDNS0-aware will still be pounding on the parent zone's name servers. [They're also much more likely to be the resolvers that are misconfigured to go to the root to reverse lookup RFC1918 addresses, don't implement negative caching and so on....] Simply adding more NS records and glue in the parent zone's delegation for a child zone is no help. For one thing, most name server implementations have a limit on the number of name servers they can handle for a delegation. Adding extra NS records is even less help when those servers have IPv6 addresses => yet bigger DNS payloads. In fact adding extra servers and/or IPv6 addresses may be worse because there's an increased likelihood of truncated responses getting sent to these non-EDNS0 resolvers, resulting in retried queries over TCP. Nasty. Aside from these DNS protocol issues, there are plenty of other good reasons for deploying anycasting for important DNS infrastructure. That's why lots of the root and TLD name server operators are doing this already. Ironically, these include the NCC's root name server. Anycasting provides increased robustness, extra redundancy, improved performance, better scalability, extra capacity/throughput, defence in depth from DDoS attacks, etc, etc. Anycasting isn't going to go away even if all the world's DNS software implemented EDNS0. Anycasting is a fact of life. And it will become more prominent in future. So if the address policy WG is reluctant to endorse special address allocations for DNS anycasting, I'd ask them to reconsider. If it helps, we could ask the DNS WG to discuss the issue and perhaps make a recommendation to the address policy WG.

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Re: [address-policy-wg] Policy Change Request - Allow address allocations for anycast DNS operation
by Peter Koch 15 Jun '04

15 Jun '04

Hello, {I'm copying this to the DNS wg list, since the protocol issues may probably be better discussed there. Hey, I *love* these [tags] :-(} [address allocation for anycast of DNS nameservers] Havard Eidnes <he(a)uninett.no> wrote: > > ------------ snip ------------ > > "Operators providing DNS for a zone served by a number of name servers > > such that the total response size when including the list of > > nameservers for the zone is close to the UDP packet size limit may > > Hm, it's not "the UDP packet size limit", it is "the packet size limit > for DNS over UDP without the application of EDNS.0". I may not have > followed things too closely, but it makes me sort of wonder why a push towards EDNS.0 is not being advocated instead of polluting the routing > space to compensate for people who have not yet upgraded their > software... Of course, people may still dream up configurations which Isn't then the parent of those trying to do anycast suffering from those resolvers unaware of EDNS0? In other words: what could the applicant do? -Peter

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reverse delegation of a /16 doesn't work with new interface
by Marc Pauls 17 May '04

17 May '04

Hello, trying to setup a reverse delegation for a /16 (where ns.ripe.net is required) through the new mnt-domains based interface at auto-dbm(a)ripe.net doesn't seem to work. After trying several times I decided to send the delegation mail to the old auto-inaddr(a)ripe.net and it worked fine. When creating a new delegation of a /16 I always thought that the mandatory ns.ripe.net becomes a delegated nameserver itself by passing it as one of the nserver: entries in the domain template. e.g: domain: 222.111.in-addr.arpa ... nserver: ns1.customer-ns nserver: ns2.customer-ns nserver: ns.ripe.net ... That always worked with auto-inaddr(a)ripe.net but doesn't with auto-dbm(a)ripe.net. The error messages given by the database: ***Warning: (related to ns2.coustomers-ns) The nameserver ns.ripe.net was found listed for the zone at ns2.comstomers-ns (10.10.10.10), but was not one of the delegated nameservers (ns2.customers-ns, ns1.customers-ns). Only the delegated nameservers should be listed anywhere for the zone. ***Warning: (related to set) Only 2 delegated nameserver(s) ns2.customers-ns, ns1.customers-ns. There should be at least 3. ***Warning: (related to set) The RIPE NCC nameserver exactly one was not present in the list of delegated nameservers for this zone (ns.ripe.net). This is required by the RIPE NCC for this type/size of zone. Of course the NS-entries in the zones are all okay and contain ns.ripe.net of course... how I wrote... with auto-inaddr(a)ripe.net it worked. All in all that means that ns.ripe.net doesn't become authorative itself by passing it to a new /16 delegation through the new interface and so the database returns error messages. kind regards, Marc.

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DNSSEC road map development meeting during RIPE
by Jaap Akkerhuis 28 Apr '04

28 Apr '04

This is a synopsis of an announcement which might be interesting for those people planning to come to the Ripe meeting. The full invitation will be published the web site: http://www.sdl.sri.com/other/dnssec/ where some more info is available. If you want to come, please register via this site (and ignore the deadline). jaap ------- An Invitation: Building a Road Map for DNSSEC Deployment Steve Crocker (steve(a)shinkuro.com) Russ Mundy (russ(a)tislabs.com) April 2004 Synopsis What has to be done to move DNSSEC from the specification to deployment? It's time to build a road map and identify any difficulties that have to be overcome. The next step is for prospective vendors, network operators and large users to get involved. We are holding a pair of one day meetings, Monday, May 3 in Amsterdam in conjunction with the RIPE meeting, and Sunday, May 23 in San Francisco in conjunction with the NANOG meeting. These meetings will be small, interactive workshops to extend the DNSSEC community and identify the hurdles. We invite interested parties to come to one or both meetings. These meetings have put together on short notice and we recognize that not everyone who is interested will be able to come. These meetings are just a first step. Notes from the meeting will be posted and other meetings will take place over the next several months. This is a community based, international effort. These meetings are being organized with the support of the U.S. Department of Homeland Security, the U.S. National Institutes of Standards and ICANN. Sponsorship will expand over the next several months. This work is open and will be reported on the net at http://www.sdl.sri.com/other/dnssec/

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K-root mirror instance deployed in Athens
by Dave Knight 27 Apr '04

27 Apr '04

Dear Colleagues, The RIPE NCC is pleased to announce the deployment of a new mirror instance of the K-root Internet root name server in Athens, Greece on April 26 2004. This node has been sponsored by the Greek Research and Technology Network (GRNET) and is located at the Athens Internet Exchange. The announcement can be found at: http://www.ripe.net/ripencc/kroot-athens-20040427.html Kind regards, Dave Knight RIPE NCC

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New Policy and Procedures for Reverse DNS Requests
by Olaf Kolkman 26 Apr '04

26 Apr '04

Dear Colleagues, (Apologies for duplicate messages) The RIPE NCC has implemented a number of changes in the policy and procedures for requesting reverse delegation. This follows the effort to streamline reverse DNS operations [1] and make it easier for network administrators to manipulate related DOMAIN objects. You should be aware of the following changes: When users want to update their reverse DNS information, they send an e-mail to <auto-dbm(a)ripe.net> (formerly this mail was sent to <auto-inaddr(a)ripe.net>). The database update program will verify the DNS information and update the RIPE Database. The information will appear in the DNS after a short delay. The policy constraints have been reduced. Previously only space assigned to End Users could be reverse delegated in DNS. This caused administrative burden to LIRs, as every time space was assigned, reverse DNS had to be set up for that space. Now reverse DNS can be set up for an entire allocation. Documentation that details the new setup and authorisation can be found at: http://www.ripe.net/reverse/ More details on these developments is provided below. * The reverse DNS policy as proposed in [3] is published as ripe-xxx. The main change to the policy is the removal of the requirement for valid assignments. Reverse delegations can also be requested by non LIRs if an appropriate "mnt-domains:" attribute is in place in the corresponding INETNUM/INET6NUM object, when submitting requests to <auto-dbm(a)ripe.net>. * The <auto-inaddr(a)ripe.net> interface will be deprecated as of 1 July 2004. To allow for a graceful transition, the "mnt-domains:" based authorisation mechanism has not been implemented for the <auto-inaddr(a)ripe.net> interface. This will continue to use reg ID based authorisation. The "mnt-by:" attribute will become mandatory. However, the existence of the "mnt-by:" attribute in DOMAIN objects is not enforced when the object is submitted through the <auto-inaddr(a)ripe.net> interface. Please contact <inaddr(a)ripe.net> if you have further questions. Olaf Kolkman New Projects, RIPE NCC Can Bican Software Engineering Dept., RIPE NCC ---------------------------------------------------------------------- References: [1] Original RDNS Project Proposal http://www.ripe.net/reverse/proposal.html [2] "mnt-domains:" Attribute Proposal http://www.ripe.net/ripe/mail-archives/dns-wg/2004/msg00007.html [3] Policy for Reverse Address Delegation of IPv4 and IPv6 Address Space in the RIPE NCC Service Region http://www.ripe.net/ripe/docs/rev-del.html [4] Webupdates http://www.ripe.net/perl/webupdates.pl [5] http://www.ripe.net/ripe/mail-archives/dns-wg/2004/msg00008.html

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