DNS Measurements
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This document discusses using Internet measurements and the RIPE Atlas platform to monitor DNS performance. RIPE Atlas allows monitoring DNS infrastructure like root name servers from thousands of global vantage points. It can troubleshoot problems, validate peering strategies, and help with content distribution planning. Both active and passive DNS measurements are covered, including analyzing zone files to assess IPv6 and DNSSEC deployment. Use cases demonstrated include monitoring root server performance and which instances clients use.
DNS Measurements
- 1. Internet/DNS Measurements Africa DNS Forum 2017 Josiah Chavula, Amreesh Phokeer AFRINIC Ltd Research & Innovation
- 2. Overview Internet Measurements ● Motivation for DNS Measurements ● RIPE Atlas measurements ● Tools, Techniques and Metrics ● Use Cases
- 3. Why Internet Measurements ● Monitor the performance of your network in real time from thousands of vantage points ● Troubleshoot problems close to your customers ● Validate your peering strategies (e.g. TraceMON routing anomalies) ● Plan your content distribution (e.g reachability and latency) ● Research (e.g. IPv6 and DNSSEC deployment and performance)
- 4. • Large-scale monitoring of Authoritative DNS (Roots, ccTLDs, etc…) • automatically detect failures • monitoring performance • Determine which instances of a name server clients/networks use • assess the impact of issues with one or more root name servers DNS Measurements (Active Measurements)
- 5. Passive DNS Measurements Analysis of zone files / resolvers’ data • Prevalence of DNS Authoritative Name servers running V6 • DNS Resolvers: prevalence of resolvers requesting AAAA records. • DNS Queries: the distribution of actual IPv6-related DNS queries. Please share DNS data!
- 6. RIPE Atlas: Probes •Global network of "probes" to measure Internet connectivity •Monitor network reachability from hundreds of vantage points •Monitor responsiveness of DNS infrastructure, such as root name servers
- 7. RIPE Atlas: Anchors •More powerful probes, monitoring regional connectivity •7 anchors in Africa
- 8. Accessing Ripe Atlas: https://atlas.ripe.net
- 9. • Root Server Performance • Server responsiveness • Performance comparison between TCP and UDP • Root Instances • which root DNS server instance gets queried by clients • Root server latencies • compare response times for DNS SOA queries to all the root DNS servers DNS Measurements
- 10. DNSMON: monitoring root zone servers
- 11. DNSMON: monitoring root zone servers
- 12. DomainMON - Up-to-date performance overview of your DNS zone
- 13. DomainMON - longitudinal performance overview of your DNS zone
- 14. Root Server Performance Performance comparison between TCP and UDP (ratio).
- 15. Which DNS root server instance is used by clients? • measure "gravitational radius" of root server instances (for servers employing anycasting) • What is the latency of different root server instances?
- 16. Which root DNS server instance is used by clients? Example: Some South African client experiences 482ms response time to Sydney versus 39ms response time to Cape Town
- 17. • Query for popular domain names to hit caches and local resolvers where appropriate Measuring end-user DNS experience?
- 18. DNS Latency Visualization: List latencies to a DNS server per probe
- 19. DNS Latency Visualization: Latency-color-coded map of probes
- 20. compare: 15ms versus 361ms DNS latency
- 21. • Compare multiple latency trends to resolvers • Charts updated in real time as data is received from the probes LatencyMON
- 22. RIPE Atlas live streaming (https://atlas.ripe.net/docs/result-streaming/, http://sg-pub.ripe.net/demo-area/atlas-stream/conn/ ) Receive measurement results as soon as they are sent by the probes - Real-time connectivity monitoring - Publish/subscribe through web sockets Three types of data: - Measurement results - Probe connection status events - Measurements metadata
- 23. The Root Canary • Measuring and monitoring the impact of the KSK rollover • Track operational impact of the root KSK • Measure validation during the KSK rollover from a global perspective • Gain immediate insight into which operators have validation problems • Monitor the state of DNSSEC validation from multiple angles • Ripe Atlas probes + test validation • using signed and bogus records
- 24. Validation status based on RIPE Atlas probes that have successfully executed tests (https://portal.rootcanary.org/rcmstats.html )
- 26. • Monitoring DNS Propagation Time / DNS Consistency • monitoring SOA timestamp propagation time • looking at the moment when a change is made by one of the registrars, and following how quickly these changes propagate. • DNS resolver hijack checker • how do we protect from “bad actors” on the Internet? How do we know that DNS resolution is coming from the “proper” place? • use RIPE Atlas probes to query a pre-set DNS record on your own server, and use a public DNS resolver with known IP addresses; match the responses; mark the probes that show inconsistent responses. • Reverse DNS statistics • dig into reverse DNS data: what percentage of delegations has issues (lame), latency in domain object creation, coverage of address space with reverse delegations. Other DNS Use Cases (From Ripe Atlas Hackathon: https://labs.ripe.net/Members/becha/results-dns-measurements-hackathon )
- 27. Web Interface Measurements (https://atlas.ripe.net/measurements/form/ )
- 28. RIPE Atlas Cousteau • A python wrapper around RIPE Atlas API - https://github.com/RIPE-NCC/ripe-atlas-cousteau - pip install ripe.atlas.cousteau • Manage measurements: - Create a measurement - Stop a measurement - Change probes involved • Fetch results from API, streaming and probes
- 30. More about Ripe Atlas • Atlas Tools: https://atlas.ripe.net/measurements-and-tools/tools/ • RESTfulAPI – https://atlas.ripe.net/docs/measurement-creation-api/ • Atlas API description – https://atlas.ripe.net/docs/rest/ • AtlasAPI tutorial – https://atlas.ripe.net/docs/measurement-creation-api/ • Public measurements – https://atlas.ripe.net/measurements/ • Map of results – https://atlas.ripe.net/results/maps/ • List of probes – https://atlas.ripe.net/probes/ • Geographical mapsof probes – https://atlas.ripe.net/results/maps/network-coverage/
- 31. AFRINIC-27 27 November to 2nd December 2017 Lagos, Nigeria AFRICOMM 2017 International Workshop on Internet Measurements Research in Africa DECEMBER 11–12, 2017 | LAGOS, NIGERIA http://africommconference.org/2017/show/IMRA Upcoming Internet Measurements Workshops