Containers Expo Blog Authors: Pat Romanski, Yeshim Deniz, Elizabeth White, Flint Brenton, Gordon Haff

Related Topics: @DevOpsSummit, Linux Containers, Containers Expo Blog

@DevOpsSummit: Blog Feed Post

DNS: What Can Go Wrong and How You Can Fix It | @DevOpsSummit #APM #Agile #DevOps

DNS enables users of all skill sets and technical knowledge levels to use this incredibly advanced resource on a daily basis

DNS: What Can Go Wrong and How You Can Fix It
By Ankit Kumar

DNS is a core component of the Internet. This rather complex system exists to perform the basic function of translating website Domain names (ex: Catchpoint.com) into an IP address. It acts as the liaison between the language that users can understand, and the address of the data center or destination in which the site is being hosted.

DNS is what shapes the modern Internet. It enables users of all skill sets and technical knowledge levels to use this incredibly advanced resource on a daily basis. Businesses that exist entirely on the Internet like online banking and ecommerce companies have not only emerged into the market, but have steadily gained a global presence.

Despite its critical role, DNS isn’t impenetrable; even with redundancies and a fast, efficient design, it’s still vulnerable to performance issues and failures. When these issues occur, it means that your applications and websites are inaccessible and users are likely feeling frustrated. Performance degradation can have serious consequences that can affect your revenue and brand reputation, so it’s crucial that your DNS is reliable and consistent.

Regardless of where your DNS is hosted (internally vs. third-party such as OpenDNS, NS1, etc.), reliability should always be a priority. To ensure it’s reliable, you must use a DNS monitor that allows you to test and analyze the results so you can make improvements. Monitoring also gives you the ability to recognize performance trends and patterns, and identify areas of concern.

Let’s take a look at some of the real world concerns that can cause DNS resolution issues.

Not using a multiple name server architecture:
DNS name servers are very important; they are the primary source that directs to the actual hostnames, which is what a client is looking for. These name servers can go down at times due to an issue (i.e. DDoS attacks, network issues with the server, etc.). This can be cause for serious concern if there is only one name server in place because the DNS resolution will fail and the end user wouldn’t be able to visit the page at all. It’s always advisable to have multiple name servers to answer DNS queries so that even if one fails, others can answer the query.

Let’s say I have a hostname www.abc.com and I have configured only one name server to handle the DNS query. So when the request reach abc.com, it gets the following information in the zone file:

abc.com   172,800   IN   NS     ns1.abc.com

Now imagine if this name server goes down; the complete DNS query will fail and the client will not be able to reach www.abc.com because there isn’t a second name server to handle failure.

Let’s look at another example: www.google.com has four name servers which enables them to handle a name server failure more effectively.

google.com   172,800   IN   NS     ns1.google.com

google.com   172,800   IN   NS     ns2.google.com

google.com   172,800   IN   NS     ns3.google.com

google.com   172,800   IN   NS     ns4.google.com

In this case, whenever any of the four name server fails, there are other three name servers which will be answering DNS queries, making sure there is not a complete outage of DNS resolution process for www.google.com.

Absence of glue records:
A glue record is the IP address of the name server that is present in the same zone file. Now, this is a very important resource record considering how the whole DNS resolution works. Let’s try to understand this with the help of an example:

Say I have a hostname www.abc.com and for that I have three name servers, which will be used in my zone file when a DNS query comes for abc.com

abc.com 172,800 IN NS ns1.abc.com

abc.com 172,800 IN NS ns2.abc.com

abc.com 172,800 IN NS ns3.abc.com

Now consider the case in which I do not give information about all three of the name servers in the form of an IP address (or glue records). Next, the DNS resolver will query one of the name servers; say ns1.abc.com is chosen. Now since the IP address of NS1 is not present in that zone file, our DNS resolver will start resolving from root, then .com, and, after querying abc.com, again it will end up with the same three name servers’ information as shown above. The DNS resolution process will be stuck in this loop forever until finally it fails. Hence, it is very important to add glue record while configuring the name server information in the zone file.

abc.com   172,800   IN   NS   ns1.abc.com

abc.com   172,800   IN   NS   ns2.abc.com

abc.com   172,800   IN   NS   ns3.abc.com

ns1.abc.com   800   IN   A

ns2.abc.com   800   IN   A

ns3.abc.com   800   IN   A

DNS cache poisoning:
To put it simply, DNS cache poisoning means incorrect DNS information. For example, if www.facebook.com starts pointing to a Google IP, that means Facebook will tell its user to search on a Google machine for Facebook content. DNS cache poisoning can occur in multiple ways, like if an attacker (middle man) gets ahold of the zone file of the authoritative name servers, they could change the value of A records and can cause incorrect DNS mapping.

It can also spread because of ISP caching wrong DNS entry, which is obtained from some compromised servers and can virtually spread from one ISP to the other and cause serious poisoning issues.

Insecure Zone transfer:
As explained earlier, having multiple name servers for a domain gives it a better chance of handling any kind of name server failure. It’s also very important for all the name servers to have updated information of the zone file, which is why you have to make sure all the Name servers have same information when it comes to zone transfer.

An insecure zone transfer can reveal a lot of critical information about a domain. Although zone transfer takes place over TCP protocol to make sure information transferred is more reliable, sometimes improper configuration of a particular name server can allow zone transfer to a third party (middle man), which means the third party will have all the critical information related to that particular domain. Hence, transferring zone information should happen between the same domain name servers. For example, if there are two name servers for example.com (NS1, NS2), then ns1.example.com should allow zone transfer only to ns2.example.com, and discard all other third-party requests for transfer.

These examples are just a few that demonstrate why monitoring is important for organizations to keep an eye on any anomalies to their DNS service. Stay tuned for a follow-up article that will examine other DNS scenarios, and how to handle the issues that can occur.

The post DNS: What Can Go Wrong and How You Can Fix It appeared first on Catchpoint's Blog.

Read the original blog entry...

More Stories By Mehdi Daoudi

Catchpoint radically transforms the way businesses manage, monitor, and test the performance of online applications. Truly understand and improve user experience with clear visibility into complex, distributed online systems.

Founded in 2008 by four DoubleClick / Google executives with a passion for speed, reliability and overall better online experiences, Catchpoint has now become the most innovative provider of web performance testing and monitoring solutions. We are a team with expertise in designing, building, operating, scaling and monitoring highly transactional Internet services used by thousands of companies and impacting the experience of millions of users. Catchpoint is funded by top-tier venture capital firm, Battery Ventures, which has invested in category leaders such as Akamai, Omniture (Adobe Systems), Optimizely, Tealium, BazaarVoice, Marketo and many more.

@ThingsExpo Stories
Dion Hinchcliffe is an internationally recognized digital expert, bestselling book author, frequent keynote speaker, analyst, futurist, and transformation expert based in Washington, DC. He is currently Chief Strategy Officer at the industry-leading digital strategy and online community solutions firm, 7Summits.
DXWordEXPO New York 2018, colocated with CloudEXPO New York 2018 will be held November 11-13, 2018, in New York City and will bring together Cloud Computing, FinTech and Blockchain, Digital Transformation, Big Data, Internet of Things, DevOps, AI, Machine Learning and WebRTC to one location.
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
Cloud-enabled transformation has evolved from cost saving measure to business innovation strategy -- one that combines the cloud with cognitive capabilities to drive market disruption. Learn how you can achieve the insight and agility you need to gain a competitive advantage. Industry-acclaimed CTO and cloud expert, Shankar Kalyana presents. Only the most exceptional IBMers are appointed with the rare distinction of IBM Fellow, the highest technical honor in the company. Shankar has also receive...
Enterprises have taken advantage of IoT to achieve important revenue and cost advantages. What is less apparent is how incumbent enterprises operating at scale have, following success with IoT, built analytic, operations management and software development capabilities - ranging from autonomous vehicles to manageable robotics installations. They have embraced these capabilities as if they were Silicon Valley startups.
DXWorldEXPO LLC announced today that ICOHOLDER named "Media Sponsor" of Miami Blockchain Event by FinTechEXPO. ICOHOLDER give you detailed information and help the community to invest in the trusty projects. Miami Blockchain Event by FinTechEXPO has opened its Call for Papers. The two-day event will present 20 top Blockchain experts. All speaking inquiries which covers the following information can be submitted by email to [email protected] Miami Blockchain Event by FinTechEXPO also offers s...
Poor data quality and analytics drive down business value. In fact, Gartner estimated that the average financial impact of poor data quality on organizations is $9.7 million per year. But bad data is much more than a cost center. By eroding trust in information, analytics and the business decisions based on these, it is a serious impediment to digital transformation.
Predicting the future has never been more challenging - not because of the lack of data but because of the flood of ungoverned and risk laden information. Microsoft states that 2.5 exabytes of data are created every day. Expectations and reliance on data are being pushed to the limits, as demands around hybrid options continue to grow.
The standardization of container runtimes and images has sparked the creation of an almost overwhelming number of new open source projects that build on and otherwise work with these specifications. Of course, there's Kubernetes, which orchestrates and manages collections of containers. It was one of the first and best-known examples of projects that make containers truly useful for production use. However, more recently, the container ecosystem has truly exploded. A service mesh like Istio addr...
As IoT continues to increase momentum, so does the associated risk. Secure Device Lifecycle Management (DLM) is ranked as one of the most important technology areas of IoT. Driving this trend is the realization that secure support for IoT devices provides companies the ability to deliver high-quality, reliable, secure offerings faster, create new revenue streams, and reduce support costs, all while building a competitive advantage in their markets. In this session, we will use customer use cases...
Digital Transformation: Preparing Cloud & IoT Security for the Age of Artificial Intelligence. As automation and artificial intelligence (AI) power solution development and delivery, many businesses need to build backend cloud capabilities. Well-poised organizations, marketing smart devices with AI and BlockChain capabilities prepare to refine compliance and regulatory capabilities in 2018. Volumes of health, financial, technical and privacy data, along with tightening compliance requirements by...
Business professionals no longer wonder if they'll migrate to the cloud; it's now a matter of when. The cloud environment has proved to be a major force in transitioning to an agile business model that enables quick decisions and fast implementation that solidify customer relationships. And when the cloud is combined with the power of cognitive computing, it drives innovation and transformation that achieves astounding competitive advantage.
DevOpsSummit New York 2018, colocated with CloudEXPO | DXWorldEXPO New York 2018 will be held November 11-13, 2018, in New York City. Digital Transformation (DX) is a major focus with the introduction of DXWorldEXPO within the program. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of bus...
Cloud Expo | DXWorld Expo have announced the conference tracks for Cloud Expo 2018. Cloud Expo will be held June 5-7, 2018, at the Javits Center in New York City, and November 6-8, 2018, at the Santa Clara Convention Center, Santa Clara, CA. Digital Transformation (DX) is a major focus with the introduction of DX Expo within the program. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive ov...
DXWorldEXPO | CloudEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
Digital Transformation and Disruption, Amazon Style - What You Can Learn. Chris Kocher is a co-founder of Grey Heron, a management and strategic marketing consulting firm. He has 25+ years in both strategic and hands-on operating experience helping executives and investors build revenues and shareholder value. He has consulted with over 130 companies on innovating with new business models, product strategies and monetization. Chris has held management positions at HP and Symantec in addition to ...
With 10 simultaneous tracks, keynotes, general sessions and targeted breakout classes, @CloudEXPO and DXWorldEXPO are two of the most important technology events of the year. Since its launch over eight years ago, @CloudEXPO and DXWorldEXPO have presented a rock star faculty as well as showcased hundreds of sponsors and exhibitors! In this blog post, we provide 7 tips on how, as part of our world-class faculty, you can deliver one of the most popular sessions at our events. But before reading...
The best way to leverage your Cloud Expo presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering Cloud Expo and @ThingsExpo will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at Cloud Expo. Product announcements during our show provide your company with the most reach through our targeted audiences.
The IoT Will Grow: In what might be the most obvious prediction of the decade, the IoT will continue to expand next year, with more and more devices coming online every single day. What isn’t so obvious about this prediction: where that growth will occur. The retail, healthcare, and industrial/supply chain industries will likely see the greatest growth. Forrester Research has predicted the IoT will become “the backbone” of customer value as it continues to grow. It is no surprise that retail is ...
Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settlement products to hedge funds and investment banks. After, he co-founded a revenue cycle management company where he learned about Bitcoin and eventually Ethereal. Andrew's role at ConsenSys Enterprise is a mul...