Information Session DNS Service level recommendations and experiences

Information Session DNS Service level recommendations and experiences

Information Session DNS Service level recommendations and experiences What is a DNS Service Level (or SLA)? SLAs are a measure of: The ability to resolve names in the name space The ability to obtain authoritative answers for domain delegations

The time taken for changes in registry data to be reflected in the name servers How to measure DNS Service Levels? These service levels are measured in a number of ways. Each has its own metric and recommended level and each deals with vastly different areas that effect DNS availability.

Service Level Measures: Overall Availability Per Name Server Availability Round Trip Time - RTT Packet Loss Average Resolution Time Scheduled Down Time DNS updates Service Level Measures - Overall Availability

This refers to the ability of an authoritative answer for DNS requests. Recommended SLA: 100% Service Level Measures Per Name Server Availability This refers to the availability of an authoritative

answer for a DNS request from each name server individually. Recommended SLA: 99.99% Service Level Measures Round Trip Time & Packet Loss This refers to the ping time and number of packets that go missing in the network that

the name server is connected to. Recommended SLA: 300ms/10% Service Level Measures Average Resolution Times This refers to the average response time for DNS queries from the time the query is received to the time the response is sent.

Recommended SLA: 250ms Service Level Measures Scheduled downtime This refers to the amount of scheduled controlled total DNS downtime allowed. Recommended SLA: No downtime

Service Level Measures DNS updates This refers to the addition, removal and modification of records in the name space, 510min updates are not uncommon, but now days they are average, with providers able to offer instant DNS updates, and propagation using IXFR. Our Recommended SLA: 20mins Max

Recommended Service Levels Summary: 100% Overall DNS Availability 99.99% Per Name Server 300ms RTT (round trip time) 10% Packet Loss maximum 250ms average resolution time No down time 20 mins Max updates How to confirm Service Levels are being met?

Normally the registry operator will perform there own SLA monitoring and report back any variations to the governing body. However you may like to measure these things yourself. Service levels such as: Overall Availability Per Name Server Availability Round Trip Time - RTT

Packet Loss Average Resolution Time DNS updates Can be measured through sampling Taking samples of each measurement over time periods is the easiest and most effective way to ensure service levels are being met. The frequency of these samples is flexible and can be decided between you and your registry

operator. Recommended sampling Frequency: Overall Availability ( 1 min ) Per Name Server Availability ( 1 min ) Round Trip Time RTT ( 1 min ) Packet Loss ( 1 min) Average Resolution Time ( 1 min) DNS updates ( 10 min )

Example: Using mrtg to sample Average Response Time `Daily' Graph (5 Minute Average) Max Response Time: 127.0 ms (0.4%)

Average Response Time: 20.0 ms (0.1%) Current Response

Time: 12.0 ms (0.0%) How to maintain good Service Levels? Choose excellent carry class data centres with redundant network connections, power etc Run multiple secondaries in diverse locations and networks

Maintain a strong and up to date understanding of DNS Use clustering at each location Use quality hardware with different OS Maintain industry best practices, such as those stated in RFC2182, 2870 etc How to co-operate with users to maintain service levels? Target larger commercial ISPs for secondary

services Making use of the existing experienced DNS companies Keep up to date, and provide discussion lists so that you can hear your communities needs. Regularly participate in discussions and show you are taking responsibility for the Name space In summary - key factors to maintaining SLAs

are: Multiple secondaries Network carrier diversity Provider diversity Monitoring Accountability Maintain industry best practice and leverage existing industry experience Thanks for listening

+ = Any Questions?

Recently Viewed Presentations

  • Ground Rules, exams, etc. (no "make up" exams) Text: read ...

    Ground Rules, exams, etc. (no "make up" exams) Text: read ...

    Similar resources favor specialists, different resources favor generalists MacArthur "Economics of Consumer Choice" Robust theorem: Diets contract when prey abundant MacArthur and Levins limiting similarity model Ambush versus Active Foragers: optimal foraging Compression Hypothesis Fisher's model of adaptation and deterioration...
  • Foster Children and Mental Health

    Foster Children and Mental Health

    Prevalence of mental health diagnoses amongst foster children is significantly higher than in the general population of children (McMillen et al., 2005; Schmid et al., 2008) Prevalence of 50% may reasonably be assumed (Bronsard et al. 2011) Attention Deficit Hyperactivity...
  • Factorial design II: Factorial ANOVA

    Factorial design II: Factorial ANOVA

    Steps to doing factorial ANOVA. Put all IVs and DVs into the correct "boxes" (SPSS/JASP) Request a plot of results. Output: See if there are significant interactions and main effects. If there is a significant interaction, run simple effects analyses
  • El Honduras By Troy Tucker The Honduran flag

    El Honduras By Troy Tucker The Honduran flag

    A diamond in the rough, Honduras, dazzles visitors with its natural beauty and diverse wildlife. Nature lovers can explore Caribbean beaches, bird-rich lakes and jungles, and the undeveloped tropical rainforest of La Mosquitia (the Mosquito Coast).
  • HEY YOU IN GRADE 10! - Weebly

    HEY YOU IN GRADE 10! - Weebly

    HEY YOU IN GRADE 10! How about a few pointers for that LITERACY TEST? * ONTARIO SECONDARY SCHOOL LITERACY TEST April - May, 2015 ORGANIZATION OF SLIDE SHOW Frequently Asked Qs Organization of Test General Tips READING General Hints Types...
  • Security and Ethical Challenges

    Security and Ethical Challenges

    A CRM system gives service reps real-time access to the same database used by sales and marketing. Requests for service are created, assigned, and managed. Call center software routes calls to agents. ... Frequently called a value chain. 1-
  • Semantics for Data Architects

    Semantics for Data Architects

    The entity Registry belongs to the Arrangement (ARR) concept. The LEI identifies a Legal Entity. In our example, JPMC NA, a Stock Corporation, an entity in the FIB-DM. The stock corporation is a subtype of the Autonomous Agent (AA). The...
  • Communication - Loudoun County Public Schools

    Communication - Loudoun County Public Schools

    Some of the examplesofOral Communication are: Face to face communication, Telephonic Communication, Public Address System (Speech), Informal rumor mill (Grape Vine), Audio & Visual Media(Radio, TV), Lectures, Conference-Interchange of views, Meetings, etc. Oral Communication: information spoken by mouth; the use...