- dns-wg - mailman.ripe.net

RIPE NCC Authoritative DNS service degraded
by Anand Buddhdev 15 Nov '13

15 Nov '13

Dear colleagues, The RIPE NCC's authoritative DNS infrastructure is experiencing a very high query rate at the moment. This query rate is more than our routers can handle, and as a result, responses from our name servers are sporadic. We are working on mitigating this denial-of-service event. Please check our service outages page for updates. http://www.ripe.net/lir-services/service-announcements Regards, Anand Buddhdev RIPE NCC

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New on RIPE Labs: New gTLD Concerns: Dotless Names and Name Collisions
by Mirjam Kuehne 12 Nov '13

12 Nov '13

Dear colleagues, We published a new article by Geoff Huston on RIPE Labs: New gTLD Concerns: Dotless Names and Name Collisions https://labs.ripe.net/Members/gih/dotless-names In the long discussions about the new generic Top level Domains (gTLD), there were two technical topics that were the subject of many assertions and little in the way of observed data. The first concerned the viability of a so-called "dotless" name, where the gTLD label itself contains an IP address in the DNS, and the second concerns the concept of "name collisions" between existing local use of a name and the same name being delegated as a new gTLD. This article explores these two topics, and adds some data to the debate in the way of observed behaviours of the way common operating systems and browsers handle names. Kind Regards, Mirjam Kuehne RIPE NCC

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PTR Record Problem
by Mehdi Sabour 07 Nov '13

07 Nov '13

Dear Colleague, I have faced a problem and I want to address it to you; I hope you can help me. I have created 77.104.67.162 PTR record in my DNS Servers and make its domain in Ripe Database 67.104.77.in-addr.arpa on Monday 4th of November. However, DNS servers do not resolve this IP address. I checked this IP in my DNS Server and Ripe database and It seems everything is OK. I promise you can help me. Best Regards. --- Mehdi Sabour OC Manager Technical Division Respina Networks & Beyond T: +98 21 84 23 00 00 F: +98 21 88 19 10 83 www.respina.net<http://www.respina.net/> ________________________________ This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system administrator. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of RESPINA. Finally, the recipient should check this email and any attachments for the presence of viruses. RESPINA accepts no liability for any damage caused by any virus transmitted by this email. ________________________________

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action item 67.1: gather input for guidance on ccTLD secondary service by the RIPE NCC
by Peter Koch 16 Oct '13

16 Oct '13

Dear WG, with reference to slide 7 in Anand's presentation <https://ripe67.ripe.net/presentations/248-RIPE67_AnandBuddhdev_DNS_update.p…> we are looking for volunteers to join a small short lived group that will look into the current situation and help inform a wg discussion with the intended goal of providing guidance to the NCC if and how to continue the ccTLD DNS secondary service. Please identify yourselves to the WG chairs at <dns-wg-chairs(a)ripe.net>. The result of our short deliberations will serve as input to the open WG discussion. Thanks, Peter

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yet another "final" agenda for the WG
by Jim Reid 15 Oct '13

15 Oct '13

There have been a couple of tweaks to what had been the final agenda. Tomáš Hlaváček will be speaking instead of Ondřej Surý and I've found 5 minutes to squeeze in an update on the ISC from its new CEO, Jeff Osborn. Here's what should be the final, definitive agenda for tomorrow. Maybe. :-) # # $Id: Agenda,v 1.8 2013/10/15 06:45:47 jim Exp $ # FINAL FINAL DNS WG AGENDA - RIPE 67 [0] Usual Administrivia 5 mins [1] ENUM WG Announcement 5 mins Niall O'Reilly, UCD [2] PMTU for better IPv6 Performance 10 mins Willem Toorop, NLnet Labs Options for utilising ICMPv6 Packet-Too-Big (PTB) messages to increase DNS responsiveness are explored. Working solutions, evaluated with RIPE Atlas, are presented. The effect of the solutions in the real world are further assessed with the help of traffic captures from SIDN and SURFnet. [3] DNS over TCP analysis 20 mins Geoff Huston, APNIC The Host requirements Specification, RFC 1123, states that "DNS resolvers and recursive servers MUST support UDP, and SHOULD support TCP". There has been some recent discussion about the viability of employing TCP rather than UDP for large DNS responses as a means of mitigating the vulnerability to large scale DNS DDOS attacks, and this got us wondering whether resolvers still supported TCP. This is a report of an experiment to measure what proportion of the Internet's users use DNS resolvers that are capable of using TCP to query authoritative name servers. [4] Defeating DNS Amplification Attacks 15 mins Ralf Weber, Nominum Discussions of amplification attacks have largely focused on authoritative servers. These attacks are beginning to use recursive resolvers. The current generation of attacks leverages home gateways that forward DNS queries coming in on their WAN interface, masking their origin when they arrive at a resolver. It's unlikely vulnerable home gateways can be updated anytime soon, so this presentation will describe how log data from DNS resolvers can be used to identify attacks and detail proposals for mitigating them without impacting legitimate DNS traffic. [5] UDP Fragmentation/PMTU attack mitigation 20 mins Tomáš Hlaváček, CZ.NIC Recent work has indicated transport- and link-level fragmentation issues are a concern for the DNS. CZ.NIC have been working on a proof of concept to illustrate these potential problems and what might be done to defend against them. [6] Open discussion of [2], [3], [4] & [5] 15 mins LUNCH BREAK [7] NCC DNS Report 10 mins Anand Buddhev, RIPE NCC [8] ISC News 5 mins Jeff Osborn, ISC/DNSco [9] Which habitat fits your name server's nature best? 15 mins Willem Toorop, NLnet Labs The performance measurements used for NSD version 4 will be discussed. The core architectural choices in the implementations of various popular name servers are explained. An analyisis given of which environments and under what circumstances these implementations flourish best. [10] Introducing Hedgehog 10 mins Dave Knight, ICANN Hedgehog, a replacement for DSC which is snazzier in many ways, has been developed for ICANN and will be published as Free/Open Source Software. [11] Client-IP EDNS Option Concerns 15 mins Florian Streibelt, TU Berlin Adoption of the proposed DNS extension, EDNS-Client-Subnet (ECS) offers unique, but likely unintended, opportunities to discover details about operational practices by ECS adopters at almost no cost. By utilising only a single residential vantage point and relying solely on publicly available information, we are able to (i) uncover the global footprint of ECS adopters with very little effort; (ii) infer the DNS response cacheability and end-user clustering of ECS adopters for an arbitrary network in the Internet; and (iii) capture snapshots of user to server mappings as practiced by major ECS adopters. While pointing out such new measurement opportunities, our work is also intended to make current and future ECS adopters aware of which operational information gets exposed when utilizing this recent DNS extension. [12] OTE's resolver infrastructure/design/rollout 20 mins Kostas Zorbadelos, Otenet * Initial presentation of the resolving service * Why anycast, motives for the service redesign * Design choices for anycast nodes in OTE's network * Software choices and anycast node setup * Transition to the new setup for existing users * Monitoring / alerting / measurement tools * Future work / discussion [13] DITL Data Analysis for ICANN gTLD Collision Study 10 mins Jim Reid, RTFM LLP Earlier this year ICANN commissioned a study into the issues and risks of name collision which may be caused by the addition of new gTLDs. This presentation describes how several terabytes of DNS traffic comprising 150+ billion queries, mostly provided by root server operators for DNS-OARC's DITL exercise, were processed and the technical challenges/constraints on doing this work. [14] AOB

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Minutes DNS-wg RIPE 66
by Jaap Akkerhuis 01 Oct '13

01 Oct '13

All, The minutes have been posted at the usual place <https://www.ripe.net/ripe/groups/wg/dns/minutes/ripe-66>. Please review so they can be approved. Thanks! jaap

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yet another final version of the agenda for Athens
by Jim Reid 01 Oct '13

01 Oct '13

Oops! There was a cut and paste error in the version of the agenda I circulated yesterday. Sorry about that. This has been fixed in the updated version below. Which should be the final version until the next change. :-) # # $Id: Agenda,v 1.7 2013/10/01 08:56:56 jim Exp $ # FINAL DNS WG AGENDA - RIPE 67 [0] Usual Administrivia 5 mins [1] ENUM WG Announcement 5 mins Niall O'Reilly, UCD [2] PMTU for better IPv6 Performance 10 mins Willem Toorop, NLnet Labs Options for utilising ICMPv6 Packet-Too-Big (PTB) messages to increase DNS responsiveness are explored. Working solutions, evaluated with RIPE Atlas, are presented. The effect of the solutions in the real world are further assessed with the help of traffic captures from SIDN and SURFnet. [3] DNS over TCP analysis 20 mins Geoff Huston, APNIC The Host requirements Specification, RFC 1123, states that "DNS resolvers and recursive servers MUST support UDP, and SHOULD support TCP". There has been some recent discussion about the viability of employing TCP rather than UDP for large DNS responses as a means of mitigating the vulnerability to large scale DNS DDOS attacks, and this got us wondering whether resolvers still supported TCP. This is a report of an experiment to measure what proportion of the Internet's users use DNS resolvers that are capable of using TCP to query authoritative name servers. [4] Defeating DNS Amplification Attacks 15 mins Ralf Weber, Nominum Discussions of amplification attacks have largely focused on authoritative servers. These attacks are beginning to use recursive resolvers. The current generation of attacks leverages home gateways that forward DNS queries coming in on their WAN interface, masking their origin when they arrive at a resolver. It's unlikely vulnerable home gateways can be updated anytime soon, so this presentation will describe how log data from DNS resolvers can be used to identify attacks and detail proposals for mitigating them without impacting legitimate DNS traffic. [5] UDP Fragmentation/PMTU attack mitigation 20 mins Ondřej Surý, CZ.NIC Recent work has indicated transport- and link-level fragmentation issues are a concern for the DNS. CZ.NIC have been working on a proof of concept to illustrate these potential problems and what might be done to defend against them. [6] Open discussion of [2], [3], [4] & [5] 15 mins LUNCH BREAK [7] NCC DNS Report 10 mins Anand Buddhev, RIPE NCC [8] Which habitat fits your name server's nature best? 15 mins Willem Toorop, NLnet Labs The performance measurements used for NSD version 4 will be discussed. The core architectural choices in the implementations of various popular name servers are explained. An analyisis given of which environments and under what circumstances these implementations flourish best. [9] Introducing Hedgehog 10 mins Dave Knight, ICANN Hedgehog, a replacement for DSC which is snazzier in many ways, has been developed for ICANN and will be published as Free/Open Source Software. [10] Client-IP EDNS Option Concerns 15 mins Florian Streibelt, TU Berlin Adoption of the proposed DNS extension, EDNS-Client-Subnet (ECS) offers unique, but likely unintended, opportunities to discover details about operational practices by ECS adopters at almost no cost. By utilising only a single residential vantage point and relying solely on publicly available information, we are able to (i) uncover the global footprint of ECS adopters with very little effort; (ii) infer the DNS response cacheability and end-user clustering of ECS adopters for an arbitrary network in the Internet; and (iii) capture snapshots of user to server mappings as practiced by major ECS adopters. While pointing out such new measurement opportunities, our work is also intended to make current and future ECS adopters aware of which operational information gets exposed when utilizing this recent DNS extension. [11] OTE's resolver infrastructure/design/rollout 20 mins Kostas Zorbadelos, Otenet * Initial presentation of the resolving service * Why anycast, motives for the service redesign * Design choices for anycast nodes in OTE's network * Software choices and anycast node setup * Transition to the new setup for existing users * Monitoring / alerting / measurement tools * Future work / discussion [12] DITL Data Analysis for ICANN gTLD Collision Study 10 mins Jim Reid, RTFM LLP Earlier this year ICANN commissioned a study into the issues and risks of name collision which may be caused by the addition of new gTLDs. This presentation describes how several terabytes of DNS traffic comprising 150+ billion queries, mostly provided by root server operators for DNS-OARC's DITL exercise, were processed and the technical challenges/constraints on doing this work. [13] AOB

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final version of the agenda for RIPE67
by Jim Reid 30 Sep '13

30 Sep '13

Colleagues, here is what should be the final version of the WG agenda for Athens. Although no further changes are anticipated, please bear in mind there is always the possibility we get over taken by events between now and Oct 15th. Hope to see most of you in Athens in a couple of weeks. # # $Id: Agenda,v 1.6 2013/09/29 14:26:04 jim Exp $ # FINAL? DNS WG AGENDA - RIPE 67 [0] Usual Administrivia 5 mins [1] ENUM WG Announcement 5 mins Niall O'Reilly, UCD [2] PMTU for better IPv6 Performance 10 mins Willem Toorop, NLnet Labs Options for utilising ICMPv6 Packet-Too-Big (PTB) messages to increase DNS responsiveness are explored. Working solutions, evaluated with RIPE Atlas, are presented. The effect of the solutions in the real world are further assessed with the help of traffic captures from SIDN and SURFnet. [3] DNS over TCP analysis 20 mins Geoff Huston, APNIC The Host requirements Specification, RFC 1123, states that "DNS resolvers and recursive servers MUST support UDP, and SHOULD support TCP". There has been some recent discussion about the viability of employing TCP rather than UDP for large DNS responses as a means of mitigating the vulnerability to large scale DNS DDOS attacks, and this got us wondering whether resolvers still supported TCP. This is a report of an experiment to measure what proportion of the Internet's users use DNS resolvers that are capable of using TCP to query authoritative name servers. [4] Defeating DNS Amplification Attacks 15 mins Ralf Weber, Nominum Discussions of amplification attacks have largely focused on authoritative servers. These attacks are beginning to use recursive resolvers. The current generation of attacks leverages home gateways that forward DNS queries coming in on their WAN interface, masking their origin when they arrive at a resolver. It's unlikely vulnerable home gateways can be updated anytime soon, so this presentation will describe how log data from DNS resolvers can be used to identify attacks and detail proposals for mitigating them without impacting legitimate DNS traffic. [5] UDP Fragmentation/PMTU attack mitigation 20 mins Ondřej Surý, CZ.NIC Options for utilising ICMPv6 Packet-Too-Big (PTB) messages to increase DNS responsiveness are explored. Working solutions, evaluated with RIPE Atlas, are presented. The effect of the solutions in the real aworld are further assessed with the help of traffic captures from SIDN and SURFnet. [6] Open discussion of [2], [3], [4] & [5] 15 mins LUNCH BREAK [7] NCC DNS Report 10 mins Anand Buddhev, RIPE NCC [8] Which habitat fits your name server's nature best? 15 mins Willem Toorop, NLnet Labs The performance measurements used for NSD version 4 will be discussed. The core architectural choices in the implementations of various popular name servers are explained. An analyisis given of which environments and under what circumstances these implementations flourish best. [9] Introducing Hedgehog 10 mins Dave Knight, ICANN Hedgehog, a replacement for DSC which is snazzier in many ways, has been developed for ICANN and will be published as Free/Open Source Software. [10] Client-IP EDNS Option Concerns 15 mins Florian Streibelt, TU Berlin Adoption of the proposed DNS extension, EDNS-Client-Subnet (ECS) offers unique, but likely unintended, opportunities to discover details about operational practices by ECS adopters at almost no cost. By utilising only a single residential vantage point and relying solely on publicly available information, we are able to (i) uncover the global footprint of ECS adopters with very little effort; (ii) infer the DNS response cacheability and end-user clustering of ECS adopters for an arbitrary network in the Internet; and (iii) capture snapshots of user to server mappings as practiced by major ECS adopters. While pointing out such new measurement opportunities, our work is also intended to make current and future ECS adopters aware of which operational information gets exposed when utilizing this recent DNS extension. [11] OTE's resolver infrastructure/design/rollout 20 mins Kostas Zorbadelos, Otenet * Initial presentation of the resolving service * Why anycast, motives for the service redesign * Design choices for anycast nodes in OTE's network * Software choices and anycast node setup * Transition to the new setup for existing users * Monitoring / alerting / measurement tools * Future work / discussion [12] DITL Data Analysis for ICANN gTLD Collision Study 10 mins Jim Reid, RTFM LLP Earlier this year ICANN commissioned a study into the issues and risks of name collision which may be caused by the addition of new gTLDs. This presentation describes how several terabytes of DNS traffic comprising 150+ billion queries, mostly provided by root server operators for DNS-OARC's DITL exercise, were processed and the technical challenges/constraints on doing this work. [13] AOB

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Provisional Agenda for Athens
by Jim Reid 15 Sep '13

15 Sep '13

Colleagues, here is the provisional (V1.0) agenda for the DNS WG at RIPE67. Please note these details are not finalised. However the speakers and topics below are confirmed. The precise running order (and times) have still to be decided. And of course things may be added, changed or dropped between now and October 16th. Watch this space. As always, please get in touch if you have suggestions for the agenda or questions on what's lined up for our next meeting Hope to see you in Athens. # # $Id: Agenda,v 1.1 2013/09/15 18:22:29 jim Exp $ # PROVISIONAL DNS WG AGENDA - RIPE 67 [0] Usual Administrivia [1] OTE's resolver infrastructure/design/rollout Kostas Zorbadelos, Otenet * Initial presentation of the resolving service * Why anycast, motives for the service redesign * Design choices for anycast nodes in OTE's network * Software choices and anycast node setup * Transition to the new setup for existing users * Monitoring / alerting / measurement tools * Future work / discussion [2] DNS over TCP analysis Geoff Huston, APNIC The Host requirements Specification, RFC 1123, states that "DNS resolvers and recursive servers MUST support UDP, and SHOULD support TCP". There has been some recent discussion about the viability of employing TCP rather than UDP for large DNS responses as a means of mitigating the vulnerability to large scale DNS DDOS attacks, and this got us wondering whether resolvers still supported TCP. This is a report of an experiment to measure what proportion of the Internet's users use DNS resolvers that are capable of using TCP to query authoritative name servers. [3] Defeating DNS Amplification Attacks Ralf Weber, Nominum Discussions of amplification attacks have largely focused on authoritative servers. These attacks are beginning to use recursive resolvers. The current generation of attacks leverages home gateways that forward DNS queries coming in on their WAN interface, masking their origin when they arrive at a resolver. It's unlikely vulnerable home gateways can be updated anytime soon, so this presentation will describe how log data from DNS resolvers can be used to identify attacks and detail proposals for mitigating them without impacting legitimate DNS traffic. [4] UDP Fragmentation/PMTU attack mitigation Ondřej Surý, CZ.NIC [5] PMTU for better IPv6 Performance Willem Toorop, NLnetLabs Options for utilising ICMPv6 Packet-Too-Big (PTB) messages to increase DNS responsiveness are explored. Working solutions, evaluated with RIPE Atlas, are presented. The effect of the solutions in the real aworld are further assessed with the help of traffic captures from SIDN and SURFnet. [6] Which habitat fits your name server's nature best? Willem Toorop, NLnetLabs The performance measurements used for NSD version 4 will be discussed. The core architectural choices in the implementations of various popular name servers are explained. An analyisis given of which environments and under what circumstances these implementations flourish best. [7] NCC DNS Report Stuckee, RIPE NCC [8] Client-IP EDNS Option Concerns Florian Streibelt, TU Berlin Adoption of the proposed DNS extension, EDNS-Client-Subnet (ECS) offers unique, but likely unintended, opportunities to discover details about operational practices by ECS adopters at almost no cost. By utilising only a single residential vantage point and relying solely on publicly available information, we are able to (i) uncover the global footprint of ECS adopters with very little effort; (ii) infer the DNS response cacheability and end-user clustering of ECS adopters for an arbitrary network in the Internet; and (iii) capture snapshots of user to server mappings as practiced by major ECS adopters. While pointing out such new measurement opportunities, our work is also intended to make current and future ECS adopters aware of which operational information gets exposed when utilizing this recent DNS extension. [9] DITL Data Analysis for ICANN gTLD Collision Study Jim Reid, RTFM LLP Earlier this year ICANN commissioned a study into the issues and risks of name collision which may be caused by the addition of new gTLDs. This presentation describes how several terabytes of DNS traffic comprising 150+ billion queries, mostly provided by root server operators for DNS-OARC's DITL exercise, were processed and the technical challenges/constraints on doing this work. [10] OpenDNSSEC Update Sara Dickinson, Sinodun Project announcements

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New on RIPE Labs: A Question of DNS Protocols (by Geoff Huston)
by Mirjam Kuehne 28 Aug '13

28 Aug '13

Dear colleagues, Please find a new article by Geoff Huston on RIPE Labs: A Question of DNS Protocols: https://labs.ripe.net/Members/gih/a-question-of-dns-protocols Kind regards, Mirjam Kuehne RIPE NCC

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