3. Goals
3
1. Understand what DNS is and how it works.
2. Cover the factors that affect webpage load times.
3. Identify important DNS features and their functions.
4. Learn some ways DNS can impact your business.
5. Segment the different types of DNS solutions available.
6. Become a more informed buyer!
#INAPDNS
4. What is DNS?
4
DNS (Domain Name
System) maintains a catalog
of domain names, such as
“internap.com”, and resolves
them into IP addresses.
Therefore anyone that has a
presence online uses DNS.
In other words, DNS is
needed for any user to find
and connect to any website.
INTERNAP.COM
243.64.13.101
#INAPDNS
5. How does DNS work?
5
Top Level DNS
Server
Local DNS
Resolver
Internap.com
Authoritative Name
Server
I want to go to
www.internap.com
Not in my
cache
#INAPDNS
6. How does DNS work?
6
Top Level DNS
Server
Local DNS
Resolver
Internap.com
Authoritative Name
Server
Authoritative Name Server
for internap.com is at
243.64.13.8
#INAPDNS
7. How does DNS work?
7
Top Level DNS
Server
Local DNS
Resolver
Internap.com
Authoritative Name
Server
www.internap.com is at
243.64.13.101
#INAPDNS
8. How does DNS work?
8
Top Level DNS
Server
Local DNS
Resolver
Internap.com
Authoritative Name
Server
www.internap.com is at
243.64.13.101
#INAPDNS
9. How does DNS work?
9
Top Level DNS
Server
Local DNS
Resolver
Internap.com
Authoritative Name
Server
www.internap.com is at
243.64.13.101
243.64.13.101
#INAPDNS
10. Important factors that impact page load times:
• Initial connections
• DNS lookups
• SSL handshakes
• Waiting to receive data from server
• Receiving/sending data to/from the server
DNS lookups are critical because they can make up a
large percentage of page load times.
What affects website load times?
10 #INAPDNS
11. What affects website load times?
11
Tested at http://tools.pingdom.com/fpt/
Category % of Load time Actual Time (s)
Wait 34.16% 0.953
Receive 32.30% 0.901
DNS 16.56% 0.462
Connect 16.98% 0.474
SSL 0% 0.000
Send 0% 0.000
www.uga.edu
Total load time: 2.79s
www.uga.edu Waterfall View
#INAPDNS
12. What affects website load times?
12
www.engagdet.com Waterfall View
Tested at http://tools.pingdom.com/fpt/
Category % of Load time Actual Time (s)
Wait 52.76% 1.894
Receive 10.06% 0.361
DNS 17.34% 0.623
Connect 16.93% 0.608
SSL 2.86% 0.103
Send 0.05% 0.002
www.engadget.com
Total load time: 3.59s
#INAPDNS
13. Managed DNS Features - Anycast
13
DNS
Server
DNS
Server
I want to go to
www.internap.comDNS
Server
DNS
Server
#INAPDNS
Internap.com
14. Managed DNS Features - Anycast
14
DNS
Server
DNS
Server
I want to go to
www.internap.comDNS
Server
Closest
name server*
DNS
Server
www.internap.com
is at 243.64.13.101
*Based on AS path length
#INAPDNS
Internap.com
15. Managed DNS Features - Anycast
15
DNS
Server
DNS
Server
I want to go to
www.internap.comDNS
Server
Closest
name server*
DNS
Server
www.internap.com
is at 243.64.13.101
*Based on AS path length
#INAPDNS
Internap.com
243.64.13.101
16. Managed DNS Features – Active Failover
16
DNS
Server
Internap.com (primary)I want to go to
www.internap.com
www.internap.com is at
243.64.13.101
Internap.com (secondary)
Health monitoring
243.64.13.101
#INAPDNS
17. Managed DNS Features – Active Failover
17
DNS
Server
Internap.com (primary)
www.internap.com is at
243.64.13.101
Internap.com (secondary)
243.64.13.101
!
Health monitoring
#INAPDNS
18. Managed DNS Features – Active Failover
18
DNS
Server
Internap.com (primary)
Internap.com (secondary)
Health monitoring
www.internap.com is at
106.19.26.102
#INAPDNS
19. Scenario:
A growing e-commerce site has been handling their DNS needs through their ISP since
inception. Recently they expanded to the EU and noticed that users were experiencing
unacceptable latency while connecting to their site. Furthermore, last month, users were
unable to reach the ecommerce site for up to 10 minutes.
Impact:
Lost Revenue
Customer Frustration
Causes:
DNS name servers not geographically close to a large percentage of users.
Routing table errors were misdirecting requests to far afield name servers.
Network congestion contributed to slow resolution of DNS queries.
A hardware failure occurred at one of the name server nodes – no DNS failover.
How DNS can impact your business
19
Increased Churn
Decreased Loyalty
Increased Acquisition Costs
#INAPDNS
20. Business Impacts
20
Average Delay in Websites when Business Performance Starts to decline:
Trac Research: http://www.slideshare.net/KenGodskind/alertsitetrac
Compuware/Gomez Annual Survey: Why Web Performance Matters
Aberdeen Group report, “The Performance of Web Applications: Customers are Won or Lost in One Second.”
4.4 seconds
Impact on conversion rate for every additional second of website load delay
-7%
Proportion online shoppers that said they’d leave for a competitor’s site
rather than suffer delays:
75%
#INAPDNS
21. Shoppers per month 85,000
Typical Conversion Rate 2.00%
Shoppers Buying Item per month 1,700
Typical Cart Size 42$
Average Revenue per Month 71,400$
Shoppers per month 75,000
Slow-site Conversion Rate 1.86%
Shoppers Buying Item per month 1,395
Slow-site Cart Size 40.74$
Average Revenue per Month 56,832$
Lost Revenue per Month 14,568$
Lost Revenue per Day 478$
Lost Revenue per Minute 0.33$
Business Impacts
21
Downtime Unacceptable Lag
7% conversion
rate reduction
3% cart size
reduction
(DNS servers completely
unavailable)
(5.4 seconds or
+1 second of incremental delay)
Shoppers per month 85,000
Typical Conversion Rate 2.00%
Shoppers Buying Item per month 1,700
Typical Cart Size 42$
Average Revenue per Month 71,400$
Average Revenue per Day 2,341$
Average Revenue per Minute 1.63$
Lost Revenue per Minute 1.63$
#INAPDNS
22. What DNS solution is right for you?
22
Manage every aspect of DNS, from
operations to infrastructure.
DIY Home-grown DNS
Control
Complexity
×Cost
?
Vulnerability
Performance
×
×
Support ?
Feature Set ?
#INAPDNS
23. What DNS solution is right for you?
23
Manage every aspect of DNS, from
operations to infrastructure.
Bundled ISP/Hoster DNS
ISP or Hoster bundles DNS with
bandwidth commit or purchase of
servers.
DIY Home-grown DNS
Control
Complexity
Cost
Vulnerability
Performance
?
?
×
×
Support ?
Feature Set ?
Control
Complexity
×Cost
?
Vulnerability
Performance
×
×
Support ?
Feature Set ?
#INAPDNS
24. What DNS solution is right for you?
24
Managed DNS
Control
Third party manage every aspect of
DNS, from operations to
infrastructure.
Complexity
Cost ?
Vulnerability
Performance
Support
Feature Set
Manage every aspect of DNS, from
operations to infrastructure.
Bundled ISP/Hoster DNS
Control
ISP or Hoster bundles DNS with
bandwidth commit or purchase of
servers.
Complexity
Cost
Vulnerability
Performance
?
?
×
×
DIY Home-grown DNS
Support ?
Feature Set ?
Control
Complexity
×Cost
?
Vulnerability
Performance
×
×
Support ?
Feature Set ?
#INAPDNS
25. Key Takeaways
25
• Don’t neglect your DNS service. This results in loss of
traffic, revenue and happy users.
• A robust Managed DNS solution provides the features,
reliability, reach and performance needed to support
todays websites and applications in addition to solving
the drawbacks of an in-house or ISP DNS solution.
• DNS can be a disaster recovery solution by using failover
to ensure your users can always find you.
#INAPDNS
26. Internap’s Managed DNS
26
Internap’s Managed DNS uses anycast routing across 24 POPs (points of presence)
worldwide to quickly send requests to the closest name server and leverages our
MIRO-enabled network to minimize latency and improve consistency. Our intuitive web
interface and customizable API provide the control and flexibility you need to quickly
get your websites up and running.
DNS POP Metros
Atlanta New York (2)
Boston Philadelphia
Chicago (2) Phoenix
Dallas San Francisco
Denver Seattle
Frankfurt Singapore
Hong Kong Sydney
Houston Tokyo
Irvine Toronto
London Washington D.C.
Los Angeles
Miami
Internet users and Internap Managed DNS POP locations
#INAPDNS
27. Further Reading
27
• Where do I learn more about DNS?
http://www.techsupportalert.com/content/what-dns-servers-do.htm
• Is DNS important?
http://www.techrepublic.com/blog/data-center/dns-painful-reminders-of-how-important-it-is/
• How do I measure my own site’s DNS performance?
http://tools.pingdom.com/fpt/
• How can DNS can help during outages?
http://www.sans.org/reading-room/whitepapers/recovery/touch-disaster-recovery-solution-continuity-
operations-33373
• Internap Managed DNS webpage and datasheet:
http://www.internap.com/network-services/ip-services/managed-dns/
#INAPDNS
OK thanks very much Ansley. I’m going to quickly walk through what we’d like your to walk away with after this webinar. We really have 6 goals for our discussion today – first we’re going to define DNS and describe how a basic DNS
Local
Downtime has a profound impact on any business and can happen to anyone and for a multitude of reasons including:
Hardware failures
Malicious attacks (DDOs, hackers)
Scheduled maintenance and upgrades
Disasters
Being down translates into loss revenue and customer loyalty. Even your search engine rankings can be affected by outages if your downtime is long enough*.
Failover is a disaster recovery solution that makes sure websites remain available in the event of an outage by automatically redirecting traffic to a backup location.
Ok thanks Ben
Main Downtime reasons:
Security
Hardware or network failures
Data center failure
Several kinds of DNS failover – active, passive, active/active, active/passive
Change slide to include graphic
Main Downtime reasons:
Security
Hardware or network failures
Data center failure
Several kinds of DNS failover – active, passive, active/active, active/passive
W
Change slide to include graphic
Home Grown DNS More times than not this is going to be an off-the shelf solution like BIND or Tiny DNS. This might practically involve 2 servers in the same location.
Home Grown DNS
Pros:
Control – Manage every aspect of DNS, from operations to infrastructure.
Cons:
Costly – Personnel and operational costs
Vulnerable – Low security and sensitive to outages
Performance – No geographically distributed servers
Basic ISP DNS services are usually offered to their customers are either a free feature or at very low cost. We’re typically talking about companies that primarily sell connectivity or hosting services and then bundle DNS as part of their base offering. Hosting providers and Domain name registrars also sometimes bundle DNS with their services making purchase easy and economical. Unfortunately, Basic ISP DNS often only consist of a couple of name servers that aren’t adequately distributed. Features like anycast, failover, broad record type support, and self service user interface are often non-existent. Further, lack of dedicated support and engineering resources can affect security, availability, and increase burdens on in-house staff to address issues.
Pros:
Price – Most ISPs provide DNS at little to no cost.
Cons:
Performance – Often ISPs are geographically restricted.
Support – Most ISPs don’t focus on DNS related issues
Thin – Limited features (no anycast, failover, etc.)
Control – DNS settings are usually handled by the ISP.
Managed DNS
Unbundled managed DNS providers often provide the most robust, flexible DNS solutions. These services offer a diverse set of features and capabilities. Given the availability of control panels and APIs, these services often provide better control and make management easier and more transparent than home grown or bundled solutions. Moreoever, security vulnerabilities are less likely because dedicated teams are handling patches and monitoring infrastructure health at all times. In addition, performance of unbundled managed DNS services are often better that other options because they include a very broad footprint of name servers , strategically placed across the world. This improves resolution times and redundancy. Internap’s Managed DNS for example has 29 PoPs across three continents. Finally, feature sets in unbundled Managed DNS offerings can be broader than other alternatives. I’m going to hand things off to Ben to cover a couple of important features to look out for in DNS services.
Pros:
Performance – Geographically dispersed servers.
Control – Easy to manage basic settings and feature rich.
Reliable – Handle security risks as well as disaster recovery.
Support – 24/7 support, analytics and SLA.
Cons:
Price – Charged by number of queries or queries per second, yet still more affordable than an in-house solution (some providers may also offer free DNS with limited features)
