How protected are you against cyber-attacks?

People often say you can’t truly understand something until it happens to you, which is true in many situations in life. We can’t imagine data security issues impact our lives.

All infrastructure is vulnerable to attack.

There is no magic platform that is completely impenetrable now and in the future. Despite what you may see in advertisements, no vendor, no firewall, no router, no hardware, no operating system, and no software product can block all possible attacks.

This is why information security is a process that begins when a system is being planned, and monitors, evaluates, and corrects security issues throughout the lifetime of the system, and continues until the system is decommissioned and its components securely disposed of.

What are the cybersecurity attacks?

Cybersecurity refers mainly to protecting internet-connected systems, including hardware, software, and data, from cyber attacks. Cyber attacks can result in the following issues:

  • Data theft
  • Ransomware installation
  • Data corruption
  • Spyware

I thought you could use a starting point, a guide you can use to do a personal security risk assessment, so you can then take the necessary actions to improve your protection from cyber-attacks.

In order for your data to be secure, it has to check 3 important factors. We want our information to:

  • be read by only the right people (Confidentiality)
  • only be changed by authorized people or processes (Integrity)
  • be available to read and use whenever we want (Availability).

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When going through the questions below and answering them honestly (no grades will be given), keep in mind these three principles. This security risk assessment is not a test, but rather a set of questions designed to help you evaluate where you stand in terms of personal information security and what you could improve.

  1. What type of information do you have stored on your computer (pictures, work documents, applications, passwords, etc.)?

It will be really useful to make a list of the different types of information you have stored:

  • Locally, on your computer
  • Online, in different apps (cloud-based or not) and on various websites.

Do you have personal emails, work documents, confidential corporate data, photos and videos of your family or personal information, such as banking credentials or passwords?

  1. Which online services do you use more often?

Think of the online services you use on a daily or weekly basis. You could list:

  • Online shopping
  • Social networking
  • Online banking
  • News websites
  • Download portals
  • Chat applications, etc.
  1. Define how valuable each asset to you.

You can use three degrees of importance: “low”, “medium” and “high”. Define this value based on the potential cost (financial, reputational or emotional) of an unauthorized person gaining access to that piece of information or service.

For example:

  • Online banking password – high value
  • Playlist stored on your music streaming service – low value.
  1. How do you keep your sensitive information safe?

Consider the following options (and others that apply to your situation):

I use strong passwords (longer than 8 characters and including symbols and numbers)

I use passwords for both my online accounts and for logging into my laptop/tablet/phone

I use two-step authentication whenever it’s available

I have set strong security questions in the event of a security breach

I have my email accounts connected so I can regain access to my information in the case of a cyber attack

I set up my phone number to receive alerts from important services (such as online banking or email) in the case my accounts should be compromised.

  1. What kind of security are you using?

Do you have an antivirus solution installed? Do you update it regularly? And, most of all, do you know that antivirus is not enough?

In order to understand why antivirus is not enough, you’ll need to learn about the difference between an antivirus and an anti-spyware product. To put it briefly:

  • When you’re already infected, antivirus programs detect if a virus is on your PC and they remove it.
  • But what you need is not to get infected in the first place.
  • So that’s why you need a tool that can work proactively to detect and block malware.
  • Another layer of protection you could use is a firewall and even an encryption application that can ensure that your data won’t be accessed in case your gadgets are stolen.

Before choosing any cybersecurity product, make sure to do some research and learn about what the product offers, check AV testing websites (AV TestAV ComparativesVirus BulletinPC Mag) and other reviews that compare options, so that you can make the best choice for you.

  1. What security software are you using against financial and data-stealing malware?

Cyber-attacks directed at collecting financial information and leaking confidential data are increasing in numbers and severity. This is why, in order to conduct online transactions with peace of mind, browse the web securely and keep your private information secure, you’ll need a dedicated product.

In order to get protection against financial malware, the solution you need should:

  • include a real-time Internet traffic scanner that scans all incoming network data for malware and blocks any threats it comes across
  • be able to provide malware detection and removal of malicious software that has already been installed onto a computer
  • have a website security scanner feature that checks the website you want to visit, detects malware and blocks it.
  1. Are you using a backup solution for your operating system or for your vital information?

Keeping your data backed up is crucial for your cyber security plan. Evaluate your options: would you rather use an external drive or a cloud based solution? Weigh in the pros and cons for each, but be sure to keep the essential information you deem valuable safe.

Backup your data regularly in order not to lose the important progress you’ve made. There’s even a World Backup Day celebration happening on March 31 to help you remember!

  1. How do you protect your shared documents (e.g. Google Docs) or gadgets (computer, tablet, etc.)?

Do any other people use your gadgets? Have you set up guest accounts for them or do they have access to the administrator account? Do you have kids that use your gadgets (and have you taught them about information security)?

I know these seem like a lot of questions, but the human factor is the most common cause for cyber-attacks because hackers know how to manipulate and trick the vulnerable categories into revealing information or installing malicious software.

Also, keeping a back-up of shared documents and files could save you the trouble of having to do the work all over again if someone should delete or modify those files. When possible, be sure to offer view-only permission and regularly check who has access to confidential information (after a colleague’s departure from the company, after a break-up with a spouse or boyfriend/girlfriend, etc.).

Maintain a vigilant attitude and, to the extent that you can, try to share valuable these what you’ve learnt from this security risk assessment with those around you, especially with the people you shared gadgets or accounts and documents stored in the cloud with.

  1. How do you manage your passwords?

You’ve probably accumulated plenty of passwords by now, which is what makes it so difficult to manage them. You may be tempted to use the same password more than once and make it easy to remember, but, by all means, NEVER do that!

 The safest way to manage your passwords is to use a password manager application, like LastPass. You should use a generator to create long, complicated passwords and store them in LastPass, and NEVER, EVER store them in your browser.

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This is especially recommended if you’re using your personal device at work. Don’t forget to password-protect your devices as well, and remember to lock/log off each time you leave them unattended.

It may take a bit to set things up at first, but, when you’re done, you’ll have more peace of mind and have a simpler way to manage your passwords.

  1. Do you regularly update the software you use?

Consider some of these choices:

Do you perform operating system updates when you’re prompted to do so?

Do you have automatic software update set up for both your OS and your applications?

Do you regularly update Oracle Java, Adobe Reader or Adobe Flash, which are known to cause 85% of security exploits that hackers use?

Do you keep your browsers updated to the latest versions?

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One of the most common and dangerous types of cyber attacks that hackers engineer are called “social engineering” strategies. These attacks entail the psychological manipulation of the victim to trick the person into divulging confidential information. The purpose can be information gathering, fraud, or system access.

So, ask yourself: do you reply to e-mails received from unknown people? Do you trust strangers and talk openly about your digital assets? Think about how you behave online and then adjust your habits so that you can become your own layer of protection.

Source: Heimdal Securitybusiness2community

All major browsers drop TLS 1.0 and 1.1 in 2020

All major web browser makers announced on October 15, 2018, that the browsers that they produce will stop supporting the standards TLS 1.0 and TLS 1.1 in 2020.

The change was announced by Google, Apple, Microsoft, and Mozilla on company websites.

Transport Layer Security (TLS) is a security protocol used on the Internet to protect Internet traffic. It uses encryption to protect the data from eavesdropping.

TLS 1.0 and TLS 1.1 are old standards. TLS 1.0 turned 19 this year, a very long time on the Internet. The main issue with TLS 1.0 is not that the protocol has known security issues but that it doesn’t support modern cryptographic algorithms.

TLS

History & Development of SSL/TLS:

Transport Layer Security (TLS), and its now-deprecated predecessor, Secure Sockets Layer (SSL), are cryptographic protocols designed to provide communications security over a computer network. Several versions of the protocols find widespread use in applications such as web browsing, email, instant messaging, and voice over IP(VoIP). Websites can use TLS to secure all communications between their servers and web browsers.

SSL and TLS are often referred to as a group – e.g. SSL/TLS

SSL which was initially invented by Netscape in 1994.

The SSL 1.0 version was never released to the public because of its serious security flaws. The SSL 2.0 was released in February 1995 and was later replaced by SSL 3.0 which is regarded as a complete redesign of the protocol performed by the American cryptographer Paul Kocher in collaboration with Netscape’s engineers in the year 1996.

Dr. Taher Elgamal, who was the chief scientist at Netscape Communications from 1995 to 1998, is considered the “Father or SSL”

Dr. Taher Elgamal

In 2014, researchers at Google disclosed the ‘POODLE’ vulnerability, which could allow attackers to decrypt encrypted connections to websites that use the SSL 3.0 protocol using a Man-in-the-Middle (MitM)attack – a popular way to intercept data.

This is where the hacker inserts a process in between the client and server through which their communication passes through, allowing the hacker to listen in on a private communication. The hacker may also be able to redirect the client to a web site controlled by the hacker where the hacker will infect the client with malware and/or commit financial fraud.

SSL 2.0 was prohibited in 2011. SSL 3.0 was also later prohibited in June 2015.

benefits-of-ssl-certificates

Image Source: ssl2buy

TLS (Transport Layer Security) is developed by the Internet Engineering Task Force (IETF) as a successor protocol to SSL.

In 1999, TLS 1.0 was designed as another protocol for SSL. Although the differences were not essential, experts stated that SSL 3.0 was less secure than TLS 1.0.

In 2006, TLS 1.1 was released. The next version TLS 1.2 released in August 2008. TLS 1.3 was released in August 2018.

TLS – a future enhancement of SSL

SSL uses the Message Authentication (MAC) algorithm; Transport Layer Security (TLS) goes a step further than this and uses keyed-Hashing Message Authentication (HMAC). What does HMAC will do? Well, it generates an identity check same as the MAC but with HMAC, it becomes tougher to break it into. TLS is a venture of Internet Engineering Task Force (IETF).

TLS protocol consists of two different layers of sub-protocols:

  • TLS Handshake Protocol: Enables the client and server to authenticate each other and select an encryption algorithm prior to sending the data
  • TLS Record Protocol: It works on top of the standard TCP protocol to ensure that the created connection is secure and reliable. It also provides data encapsulation and data encryption services.

Even though TLS 1.3 was first announced in 2014, it was released this April via OpenSSL. The distribution is still not global yet. There are millions of websites that need to upgrade to the latest version.

TLS 1.3 is currently supported in both Chrome (starting release of 66 version) and Firefox (starting with release 60), and in development for Safari and Edge browsers.

Benefits of using TLS 1.3:

  •  Faster connections

In the previous versions, two round-trips were needed to establish a secure connection. This process takes place before any actual data is transferred and lasts for hundreds of milliseconds.

With TLS 1.3 there is only one round-trip necessary to create a secure connection. This cuts the encryption latency by half!

TLS 1.3

TLS 1.3 speeds up the previously established connections even more with so-called “zero-round trip time” (0-RTT) mode. TLS 1.3 “remembers” previously shared keys and allows to send early data when resuming previous sessions.

Unfortunately, 0-RTT could be a potential threat. Attackers could access your 0-RTT communication and duplicate the flight of 0-RTT data. If your pre-shared keys are not expired, the server will accept attacker’s 0-RTT data and respond to it. This is especially dangerous for POST HTTP requests, e.g. “/buy-something”.

In order to prevent any harm, servers that allow 0-RTT should implement the anti-replay mechanism and limit 0-RTT calls to only some requests. Currently, TLS 1.3 does not provide and even cannot provide inherent replay protections for 0-RTT.

  • Improved Security

With a “less is more” approach, TLS 1.3 removed broken and vulnerable pieces of the previous protocols. Having done this, TLS 1.3 enhances security and its implementation is much simpler for developers.

Moreover, TLS 1.3 improves the safety of previous connection by securing session resumption with a PFS (Perfect Forward Secrecy) mechanism. Therefore, an attacker won’t be able to decrypt previous traffic even if he gains access to the session encryption key. In other words, all sessions and even session resumptions are individually protected.

Source: GhacksWikipediassl2buycdn77,

Tor Browser

Tor is free software for enabling anonymous communication. The name is derived from an acronym for the original software project name “The Onion Router”.

Tor directs Internet traffic through a free, worldwide, volunteer overlay network consisting of more than seven thousand relays to conceal a user’s location and usage from anyone conducting network surveillance or traffic analysis. Using Tor makes it more difficult to trace Internet activity to the user: this includes “visits to Web sites, online posts, instant messages, and other communication forms”.

Tor’s intended use is to protect the personal privacy of its users, as well as their freedom and ability to conduct confidential communication by keeping their Internet activities from being monitored.

Tor

History of Tor:

Tor is based on the principle of ‘onion routing’ which was developed by Paul Syverson, Michael G. Reed and David Goldschlag at the United States Naval Research Laboratory in the 1990’s. The alpha version of Tor, named ‘The Onion Routing Project’ or simply TOR Project, was developed by Roger Dingledine and Nick Mathewson. It was launched on September 20, 2002. Further development was carried under the financial roof of the Electronic Frontier Foundation (EFF).

The Tor Project Inc. is a non-profit organization that currently maintains Tor and is responsible for its development. The United States Government mainly funds it, and further aid is provided by the Swedish Government and different NGOs & individual sponsors.

How Tor Works?

Tor works on the concept of ‘onion routing’ method in which the user data is first encrypted and then transferred through different relays present in the Tor network, thus creating a multi-layered encryption (layers like an onion), thereby keeping the identity of the user safe.

tor-working1

One encryption layer is decrypted at each successive Tor relay, and the remaining data is forwarded to any random relay until it reaches its destination server. For the destination server, the last Tor node/exit relay appears as the origin of the data. It is thus tough to trace the identity of the user or the server by any surveillance system acting in the mid-way.

Is it safe or legal to use the Tor browser?

Yes, it’s safe and legal to use Tor browser.

But one more thing, it depends on your content, if you are visiting legal content with Tor then it’s legal.

But if you are doing something wrong with the help of Tor then it may create trouble for you.

Detailed Explanation:

The internet is like a glacier. The tip of the glacier or the Surface Web are parts of the Internet that you can find from a search engine. But there is a large part (said to be around 90%) of the Internet that cannot be found by search engines. This forms the Deep Web. For example, when you go to Facebook from your browser and see the login page, you are on the surface web. This page can be found by using a normal search engine or by directly going to its URL. However, the moment you log in to your account, you are inside the deep web. Your Facebook feed cannot be accessed by a search engine. You need to go through a door of sorts to access it.

Dark Web

There, however, is a darker part of Deep Web called the Dark Web. This is where the bad guys come in. This is the place where there are marketplaces for drugs, illegal guns, stolen credit cards, and even professional assassins. And that’s not even the worst part of it. Needless to say, those guys running these sites would be absolutely destroyed if their identities are revealed. Thus they operate on the dark web. These websites have the suffix of .onion and can only be accessed by special browsers like TOR. This is what TOR is infamous for. Sure there are people who use it for genuine, privacy concerns; but a lot of people use it as an access point to the dark web.

Using TOR is not illegal, but visiting dark websites engaging in activities that are illegal in your country will be illegal. You can still use it for your day to day activities, but remember that it will be slower than your normal browsers as the data is passed across many nodes as I mentioned above.

TOR Latest Update:

The Tor Project team has released Tor Browser 8.0, a brand-new version of the web browser to the public recently.

Tor Browser is based on Mozilla Firefox; more precisely on Mozilla’s Extended Support Release version of the Firefox web browser. Tor Browser 8.0 is based on Firefox 60.2 ESR. Tor Browser includes Tor which users of the web browser can use to connect to the Tor network to anonymize their Internet connection and various improvements especially when it comes to online privacy.

Tor Browser

How to uninstall TOR browser?

Tor Browser does not affect any of the existing software or settings on your computer. Uninstalling Tor Browser will not affect your system’s software or settings.

Removing Tor Browser from your system is simple:

  1. Locate your Tor Browser folder. The default location on Windows is the Desktop; on Mac OS X it is the Applications folder. On Linux, there is no default location, however, the folder will be named “tor-browser_en-US” if you are running the English Tor Browser.
  2. Delete the Tor Browser folder.
  3. Empty your Trash

Note that your operating system’s standard “Uninstall” utility is not used.

Tor Alternatives:

Hornet is a new anonymity network that provides higher network speeds compared to Tor. I2P (Invisible Internet Project) and Freenet are other anonymity networks which can act as Tor alternatives. Also, Tails and Subgraph OS are Linux-based distributions with built-in Tor support.

Source:  wikipediatorprojectfossbytesArpit-Kubadiaeffwinmyst

 

The top 10 features of Windows Server 2016

Windows Server 2016 as compared to the previous version focuses more on cloud and virtualization. The top 10 features of 2016 version are as follows:

1. Windows Nano Server

Nano Server is a pared down headless version (no local login) of Windows Server. Nano Server will have a 93% smaller VHD size, 92% fewer critical bulletins and 80% fewer required reboots. Nano Server is a Windows Server installation options and it’s completely headless – there’s no GUI and no command prompt. Nano Server is designed to run Hyper-V, Hyper-V cluster, and Scale-Out File Servers (SOFSs) and cloud service applications.

2. Windows Server Containers and Hyper-V Containers

The next biggest change in Windows Server 2016 will be support for containers. Containers enable you to isolate your applications from the underlying OS improving the deployment and reliability of those applications. Windows Server 2016 will provide two kinds of native containers: Windows Server Containers and Hyper-V Containers.  Windows Server Containers are isolated from each other, but they run directly on the Windows Server 2016 OS. Hyper-V Containers provide enhanced isolation by running the containers from a Hyper-V VM.

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3. Docker Support

Docker is an open-source engine that’s used for building, running and managing containers. Docker containers were originally built for Linux but the next version of Windows Server will provide built-in support for the Docker engine as well. A new open-source Docker engine project has been built for Windows Server with Microsoft participating as an active open source community member. You can use Docker to manage Windows Server and Hyper-V Containers.

4. Rolling upgrades for Hyper-V and Storage clusters

One of the biggest new changes for Hyper-V in Windows Server 2016 is rolling upgrades for Hyper-V clusters. The new rolling upgrades feature allows you to add a new Windows Server 2016 node to a Hyper-V cluster with nodes that are running Windows Server 2012 R2. The cluster will continue to run at the Windows Server 2012 R2 functional level until all of the cluster nodes have been upgraded to Windows Server 2016. When the cluster has mixed level nodes the management must be done from Windows Server 2016 or Windows 10. New VMs on a mixed cluster will be compatible with the Windows Server 2012 R2 feature set.

5. Hot add & remove of virtual memory network adapters

Another great new feature in Windows Server 2016 Hyper-V is the ability to add and remove the virtual memory and virtual network adapters while the virtual machine is running. In previous releases, you need to use dynamic memory to change the minimum and maximum RAM settings of a VM that is running. Windows Server 2016 enables you to change the allocated RAM while the VM is active even if the VM is using static memory. Likewise, you add and remove network adapters while VM is running.

6. Nested virtualization

Added primarily for the new container support, Windows Server 2016’s nested virtualization capabilities will also be a handy addition for training and lab scenarios. With this new feature, you are no longer limited to running the Hyper-V role on a physical server. Nested virtualization enables you to run Hyper-V within a Hyper-V virtual machine.

7. PowerShell Direct

PowerShell is a great management automation tool but it can be complicated to get it to run remotely against your VMs. You need to worry about security policies, firewall configurations, and your host networking configuration. PowerShell Direct enables you to run PowerShell commands in the guest OS of a VM without needing to go through the network layers. Like VMConnect (the remote console support provided by the Hyper-V Manager) it requires zero configuration it connects directly to the guest VM and all you need are authentication credentials for the VM’s guest OS.

8. Linux Secure Boot

Another new feature in Windows Server 2016 Hyper-V is the ability to enable secure boot for VMs with Linux guest operating systems. Secure Boot is a feature of the UEFI firmware specification incorporated in Generation 2 VMs that protects the VM’s hardware kernel mode code from being attacked by rootkits and other boot-time malware. Previously, Generation 2 VMs supported Secure Boot for Windows 8/8.1 and Windows Server 2012 VMs but not VM’s running Linux.

9. New Host Guardian Service and Shielded VMs

The Host Guardian Service is a new role in Windows Server 2016 that enables shielded virtual machines and protects the data on them from unauthorized access – even from Hyper-V administrators. Shielded VMs can be created using the Azure Management Pack Portal. Standard VMs can also be converted to Shielded VMs. With Shielded VMs Hyper-V virtual disks can be encrypted with BitLocker.

10. Storage Spaces Direct

Windows Server 2016 also has a number of storage system improvements one of the most important is the new Storage Spaces Direct feature. Storage Spaces Direct is the evolution of the previous Storage Spaces technology found in Windows Server 2012 R2. Windows Server 2016 Storage Spaces Direct allows a cluster to access JBOD storage in an external enclosure like Windows Server 2012 R2 or it can also allow access to JBOD and SAS disks that are internal to the cluster nodes. Like the previous release, Store Spaces form the basis for Storage Pools and they support both SSD and HDD disks and data tiering.

Source: itprotoday

What is the latest version of Wi-Fi?

What is the latest version of Wi-Fi?

It is — Wi-Fi is 802.11ax.

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The Wi-Fi Alliance—the group that manages the implementation of Wi-Fi—has announced that the next version of Wi-Fi standard, which is 802.11ax, will use a simpler naming scheme and will be called Wi-Fi 6.

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Wi-Fi 6, based on the IEEE 802.11ax standard, will offer higher data rates, increased capacity, good performance—even in dense environments (such as stadiums or public venues) and improved power efficiency, making it perfect choice for smart home and IoT uses).

Another improvement Wi-Fi 6 will bring is improved efficiency, which means a lower power draw, which means less of a strain on battery life (or lower figures on your electricity bill).

Wi-Fi 6 can now divide a wireless channel into a large number of subchannels. Each of these subchannels can carry data intended for a different device. This is achieved through something called Orthogonal Frequency Division Multiple Access, or OFDMA. The Wi-Fi access point can talk to more devices at once.

The new riderless standard also has improved MIMO—Multiple In/Multiple Out. This involves multiple antennas, which let the access point talk to multiple devices at once. With Wi-Fi 5, the access point could talk to devices at the same time, but those devices couldn’t respond at the same time. Wi-Fi 6 has an improved version of multi-user or MU-MIMO that lets devices respond to the wireless access point at the same time.

When Will You Get It?

Some routers may already advertise “802.11ax technology,” but Wi-Fi 6 isn’t finalized and here yet. There also aren’t any Wi-Fi 6 client devices available yet, either.

The Wi-Fi Alliance expects the standard to be finalized and hardware to be released sometime in 2019.

A Brief History of Wi-Fi

Final

Source: thehacker newsblog.eero, techspot,  howtogeek, wi-fi

 

 

DNS Terminology

In this post, I am going to give few basic DNS components before going to discuss the DNS functionality in depth in technical terms.

Who invented the DNS?

Paul V. Mockapetris (born 1948 in Boston, Massachusetts, US) is an American computer scientist and Internet pioneer, who, together with Jonathan Bruce Postel (August 6, 1943 – October 16, 1998) invented the Internet Domain Name System (DNS)

DNS Inventors

Paul has dual B.S. degrees in Physics and Electrical Engineering from MIT, and a Ph.D. in Information and Computer Science from the University of California, Irvine.

Postel has done his B.S. degree, M.A in Engineering and Ph.D. in Computer Science from UCLA.

Domain Terminology:

There are many terms used when talking about domain names and DNS that aren’t used too often in other areas of computing.

Domain Name System

The domain name system, more commonly known as “DNS” is the networking system in place that allows us to resolve human-friendly names to unique addresses.

Domain Name

A domain name is a human-friendly name that we are used to associating with an internet resource. For instance, “google.com” is a domain name. Some people will say that the “google” portion is the domain, but we can generally refer to the combined form as the domain name.

The URL “google.com” is associated with the servers owned by Google Inc. The domain name system allows us to reach the Google servers when we type “google.com” into our browsers.

IP Address

An IP address is what we call a network addressable location. Each IP address must be unique within its network. When we are talking about websites, this network is the entire internet.

IPv4, the most common form of addresses, are written as four sets of numbers, each set having up to three digits, with each set separated by a dot. For example, “111.222.111.222” could be a valid IPv4 IP address. With DNS, we map a name to that address so that you do not have to remember a complicated set of numbers for each place you wish to visit on a network.

Top-Level Domain

A top-level domain, or TLD, is the most general part of the domain. The top-level domain is the furthest portion to the right (as separated by a dot). Common top-level domains are “com”, “net”, “org”, “gov”, “edu”, and “io”.

Top-level domains are at the top of the hierarchy in terms of domain names. Certain parties are given management control over top-level domains by ICANN (Internet Corporation for Assigned Names and Numbers). These parties can then distribute domain names under the TLD, usually through a domain registrar.

Hosts

Within a domain, the domain owner can define individual hosts, which refer to separate computers or services accessible through a domain. For instance, most domain owners make their web servers accessible through the bare domain (example.com) and also through the “host” definition “www” (www.example.com).

You can have other host definitions under the general domain. You could have API access through an “api” host (api.example.com) or you could have ftp access by defining a host called “ftp” or “files” (ftp.example.com or files.example.com). The hostnames can be arbitrary as long as they are unique for the domain.

SubDomain

A subject related to hosts are subdomains.

DNS works in a hierarchy. TLDs can have many domains under them. For instance, the “com” TLD has both “google.com” and “ubuntu.com” underneath it. A “subdomain” refers to any domain that is part of a larger domain. In this case, “ubuntu.com” can be said to be a subdomain of “com”. This is typically just called the domain or the “ubuntu” portion is called an SLD, which means second level domain.

Likewise, each domain can control “subdomains” that are located under it. This is usually what we mean by subdomains. For instance, you could have a subdomain for the history department of your school at “www.history.school.edu“. The “history” portion is a subdomain.

The difference between a hostname and a subdomain is that a host defines a computer or resource, while a subdomain extends the parent domain. It is a method of subdividing the domain itself.

Whether talking about subdomains or hosts, you can begin to see that the left-most portions of a domain are the most specific. This is how DNS works: from most to least specific as you read from left-to-right.

Fully Qualified Domain Name

A fully qualified domain name, often called FQDN, is what we call an absolute domain name. Domains in the DNS system can be given relative to one another, and as such, can be somewhat ambiguous. An FQDN is an absolute name that specifies its location in relation to the absolute root of the domain name system.

This means that it specifies each parent domain including the TLD. A proper FQDN ends with a dot, indicating the root of the DNS hierarchy. An example of an FQDN is “mail.google.com.”. Sometimes software that calls for FQDN does not require the ending dot, but the trailing dot is required to conform to ICANN standards.

Name Server

A name server is a computer designated to translate domain names into IP addresses. These servers do most of the work in the DNS system. Since the total number of domain translations is too much for any one server, each server may redirect the request to other name servers or delegate responsibility for a subset of subdomains they are responsible for.

Name servers can be “authoritative”, meaning that they give answers to queries about domains under their control. Otherwise, they may point to other servers, or serve cached copies of other name servers’ data.

Zone File

A zone file is a simple text file that contains the mappings between domain names and IP addresses. This is how the DNS system finally finds out which IP address should be contacted when a user requests a certain domain name.

Zone files reside in name servers and generally define the resources available under a specific domain, or the place that one can go to get that information.

Records

Within a zone file, records are kept. In its simplest form, a record is basically a single mapping between a resource and a name. These can map a domain name to an IP address, define the name servers for the domain, define the mail servers for the domain, etc.

 

Source: internet hall of fame, digitaloceanwikipedia

 

What is DNS and how it works

DNS stands for Domain Name System, is the backbone that runs the Internet.

It is a database that works like a phone book for the internet, converts a domain name, such as “www.example.com,” to a machine-readable IP address, such as “22.231.113.64”.

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The internet is built up on two namespaces. The domain namespace and the IP address namespace. The translation of one to another is the service which is provided by DNS.

Explanation about DNS in Simple Terms:

DNS is very similar to the postal or telephone addressing system most countries have, with two main components: a name, and a more detailed, numerical address. If you’re sending a letter to someone, say, Jennifer who lives in Manhattan, you’d address it such:

Jennifer Aniston,

100 5th Avenue,

New York, NY 10027

With the Internet, the “name” is called a domain, and the “numeric address” part is an IP (Internet Protocol) address. But unlike sending a letter, as a regular user on the Internet, you don’t have to know the numeric address of your site, just the domain name!

Each domain (in the form of http://www.domainname.com) has a specific IP address it corresponds to. This IP address indicates the “home” or server where the web page being requested is being hosted.

Note:  Although, these procedures appear to be lengthy; however, they can happen within a tenth of a second. It is so fast that the entire process can occur before a blink of an eye.

DNS The IP Address:

xxx.xxx.xxx.xxx – where each ‘xxx’ is a number from 0-255

If you have a dedicated IP address, there will be only one domain at your “house” address. Very few commercial hosting options offer dedicated IPs with their basic plans, and usually there are hundreds to thousands of domains being addressed to the same server. So, your address is more likely to be an apartment building instead of a single-family house.

 DNS Name Servers / Authoritative Name Server: Your Global Directory Assistance

Another important player in this DNS world is the “Name Server” which is the equivalent of your local post office. They know where you live and that when a letter arrives with your name and address, they confirm and ensure that it reaches its final destination.

Each domain has just one Name Server that is in charge of keeping that domain’s information and IP addresses. Simply, when your change your IP address or “home,” your domain’s name server passes the word on the internet (with the help of routers, which we’ll talk about later) to the rest of the internet so a request directed to your website will find you.

What Happens When You Change Web Hosting

If you were moving your physical house, you’d have to notify the local post office or city hall with your new address. With your website, since you’re moving your data from one “house” to another, you need to update your site’s address, too. Usually this will require you changing the IP address to reflect the new hosting company’s server where your information will reside. Your hosting company can provide the correct IP address for you.

  • In the DNS, you’ll delete the current “address” and then insert the new IP address of your new hosting.
  • The name server notices that the DNS for your domain has changed, and usually within 24-48 hours, the name server will notify the rest of its network, which in turn will propagate the information throughout the internet.
  • The next time someone types in http://www.domainname.com, the request will be sent to your new address!

Advanced DNS Questions

  • Can you have multiple IP addresses for a single domain? Yes, much like Lifestyles of the Rich and Famous, sites which are very popular often have multiple “houses” – and often this is done with sites that have a lot of traffic and are using multiple servers to meet the demand.
  • Can multiple domains respond to the same (IP) address? Yes, as mentioned above, many commercial hosting solutions offer low-priced hosting because they can put hundreds or thousands of sites/domains on the same server since the traffic demands are so low. Depending on the traffic that comes to your site, you’ll probably never notice.

Keep reading, Keep learning 😊

Source: whenihavetimecloudflare