DNS outage – What is it?

Have you ever heard about a DNS outage? If the answer is no, no worries. You are in the right place. In this article, we will take place at what it purpose is, what can cause it, and how you protect against it.

DNS outage – definition

A DNS outage, also known as DNS downtime, occurs when the DNS fails to work correctly for an extended period of time. This means that you won’t find the IP address if you look for the domain name. Users will instead perform DNS requests to visit your domain. The DNS recursive server will request the domain’s authoritative nameserver, but it will receive an error message as a response.

Factors that cause a DNS outage

We can agree that the DNS outage is a really troublesome moment. However, it can be caused by different things, one of which are:

  • An occurrence in the data center (the site of the authoritative name server). The “cloud” is located in a data center or multiple data centers, not in the sky. And while such locations are safe, they are not foolproof. Especially when it comes to natural disasters, power outages, and other issues. Several things can cause your authoritative name server to go offline.
  • The upkeep of authoritative name servers. Updates or reboots are occasionally required as part of routine maintenance. This disables the server’s ability to respond to DNS requests.
  • Denial-of-Service and Distributed Denial-of-Service attacks. DoS and DDoS assaults aim to cause a denial of service. You will experience a DNS outage if they succeed.
  • Configuration errors. DNS outages can be caused by a variety of human errors when configuring DNS. Script errors, incorrectly typed IP address, firewall configuration issues, etc.

How can you prevent it?

There are different ways to protect you against DNS outage. Here are some of them:

  1. Load balancing service. Having a lot of traffic might be a double-edged sword. They could result from hard labor or indicate a DoS or DDoS attack in the process. In addition, DNS load balancing is an effective way to spread traffic across all of a network’s servers. You can avoid overloading individual servers, deal with traffic spikes, and handle excessive traffic in general.
  2. DDoS protection service. Advanced and continuous monitoring, firewalls, software, hardware, and DDoS deflation to absorb the attack, among other things.
  3. Secondary DNS service. You already have a DNS service provider (Primary DNS). You could hire a separate provider and set them up as Secondary nameservers using their various Secondary DNS servers. A copy of the zone file and DNS records will be stored on these servers. As a result, they’ll be able to reply to DNS requests the same way as Primary DNS does. You’ll have a backup in case the final one goes down.
  4. Monitoring service. The only way to know traffic like the back of your hand is to monitor it continually. You can distinguish between typical and abnormal traffic this way. You can take action based on traffic behavior to avert an attack or deal with a regular spike in traffic. Current solutions allow you to monitor specific places in real-time to identify whether the problem is local, regional, global, and so on.

Conclusion

Now you are familiar with the DNS outage and its consequences. Don’t let it hitch a ride on your system, but take preventive measures to protect yourself.

3 DNS commands for testing your network

In our post today, we are going to look at the best 3 DNS commands that you can use for testing your network. You can use them to examine critical information such as your DNS records and the state of your network. Furthermore, it makes no difference whether you’re running Windows, macOS, or Linux. So, let’s clarify which DNS commands are the most frequent and explain a little more about them.

Nslookup command

One of the most commonly used DNS diagnostic commands is NSLookup. It has the advantage of being available on all of the major operating systems (OS). It allows you to view all types of DNS records. In addition, it also has a number of choices.

To see all of the accessible DNS records, use the NSLookup command. Write the following in the command line:

$ nslookup -type=any exampledomain.com

* Replace exampledomain.com with the domain name that you want to test.

It will display all of the accessible DNS records for the domain in question. If you wish to see a specific DNS record, change the type to NS, A, AAAA, MX, SOA, etc. You can input another domain name or IP address after the DNS type.

Dig command

On macOS, the dig command is one of the pre-installed DNS commands. You can rapidly install the command whether you’re using Linux or Windows. It’s a valuable and useful DNS troubleshooting tool. This command can display information about any DNS record type. You can also explore your nameservers, traceroute both IPv4 and IPv6 addresses, and verify a specific port. Troubleshooting with the Dig command is simple and quick, and it’s well worth your time.

For example, if you want to see all the data for a specific domain, type in the command line:

$ dig exampledomain.com any 

* Replace exampledomain.com with the domain name that you want to test.

Simply substitute the domain name or IP address for the one you want to see. The Dig command is great since it gives you all of the information you need regarding the query you asked for. If you want a more specific result, you can use one of the several options provided by the Dig command.

Host command

The Host commands are fairly similar to the Dig commands in terms of functionality. As a result, you can use it to see the available DNS records and use it to troubleshoot DNS issues. You can also use many options to check an IP address or domain name, do a reverse lookup, discover the domain’s nameservers, or edit DNS queries. The Host command, like the Dig command, is built-in on Linux. As a result, you have complete freedom in selecting which one to utilize.

If you want to see all the available information about a domain, type the following command:

$ host -a exampledomain.com

* Replace exampledomain.com with the domain name that you want to test.

Conclusion

In conclusion, we can say that these DNS commands are really helpful for testing your network. They are easy and simple to use. Be applying the suggested commands whenever and however you wish. They will, in fact, offer you with the information you seek.

3 popular DNS attack types and how to prevent them? 

Computer hackers frequently use security gaps or unpatched weaknesses in the domain name system to launch DNS attack types. In this article, we will take a look at the most popular of them that you should be aware of and how to avoid them.

DDoS amplification attack

Let’s begin our DNS attack types list. The first one is DDoS amplification attacks. The goal of a DNS attack like this is to boost traffic to unmanageable levels. Due to the fact that UDP does not authenticate, cybercriminals send a DNS request to obtain the IP address as well as additional DNS information to ensure that the response is enormous.

Furthermore, attackers can change the requests for all of those enormous answers to go directly to the target, overwhelming it with information it didn’t ask for. The excruciating downtime will be the end outcome.

How to avoid this attack? An Anycast network can help since it contains a large number of DNS servers that can filter and manage fraudulent traffic. It can be screened without harming the network if the capacity is sufficient. 

DNS spoofing

The second most popular attack is DNS spoofing (also known as DNS poisoning). It is a relatively frequent DNS attack that includes the bad actor inserting changed DNS records into the cache memory of DNS resolvers. The IP address for the changed records is frequently different from the original name records. Visitors are led to the bad actor’s website. They can communicate sensitive information that could be exploited for a variety of illicit purposes, such as stealing money or stealing identities.

Often, the victims are completely unaware that there is an issue. Instead, they are led to a site that appears to be quite similar to what they were looking for.

It’s challenging to keep safe from such an attack because most people don’t double-check a domain’s IP address before utilizing it. However, we can protect ourselves by installing anti-virus software on our computers, avoiding suspicious links, and double-checking a website’s legitimacy before using our credit cards.

DNS tunneling

The last critical DNS attack is DNS Tunneling. It takes advantage of the DNS to encrypt (tunnel) malware and other information in DNS queries and responses (client-server way).

This is how it works in a nutshell. A criminal registers a domain and connects its name server to its own. A tunneling trojan software is installed in this last step. When a machine is infected, it sends a request to a DNS resolver server. Because DNS is allowed, DNS requests can freely pass across firewalls. The danger begins here. The resolver sends the request to the criminal’s server, and the criminal and the target establish a connection through the DNS resolution server. Because the connection between the target and the criminal is not direct, this hides and makes it challenging to identify the criminal’s computer.

How to prevent DNS Tunneling? Install a DNS effective firewall as the first line of defense to detect intrusions, odd DNS requests, answers, and patterns.

Conclusion

As you can see, DNS service is critical for keeping your websites and online services operational daily. However, it is constantly in danger. So, before it’s too late, take care of your DNS protection.

List of DNS records to improve your Email security

These DNS records are going to help you set the grounds for extremely secure and safe email communication. So, let’s start with our short list.

A record

One of the most popular DNS records is the A record, also known as an Address record. It points a domain name to its corresponding IP address (IPv4 address). Its purpose is fundamental. In addition, it shows that the particular domain name is associated with that IP address. However, it does not direct the mail servers, and they wouldn’t know where they should send email messages.

MX record

MX record, or Mail exchanger record, is one of the most popular DNS records. Its main purpose is to show which is the mail server responsible for receiving email messages for the particular domain name. It is important to note that, in case there is a mistake in the configuration of your MX record, or it does not exist at all for your domain name, you won’t be capable of receiving email messages. Therefore, if you desire to have proper receiving mail service, you should definitely set an MX record and be really careful.

PTR record

The Pointer record, or simply for short PTR record, is another essential type of DNS record for your email and email security. Its purpose is to link an IP address (IPv4 or IPv6) to its corresponding domain name. Its goal is absolutely the opposite compared to the A record. It is used to provide trust and confirmation that the particular domain name (hostname) is actually related to the specific IP address. Therefore, it is considered an essential part when you want to establish properly working outgoing mail servers. In case you do not have such a DNS record or you have made a mistake in the configuration of it, the emails you send are going to be marked as spam messages and rejected right away. That is something nobody wants. Therefore you should be aware and set everything correctly.

SPF record

The SPF (Sender Policy Framework) record is a simple TXT record that provides information with a list of all the IP addresses that are allowed to send an email message on behalf of your domain name. Thanks to it, the recipient’s mail server is able to check and verify that the email is actually coming from your domain. It helps prevent DNS spoofing and phishing attacks.

DKIM record

DKIM (DomainKeys Identified Mail) record is another TXT record that serves for email authentication. It allows the recipient’s server to check if the sender is actually the one that is claiming to be and prevent receiving a message from a forged sender. It is really valuable for detecting and stopping email spam and phishing.

Thanks to the provided encryption key and digital signature, it is able to verify that the message was not falsified or modified. Additionally, it improves the security of your email deliverability.

DMARC record

DMARC (Domain-based Message Authentication, Reporting, and Conformance) record is also a TXT Record published for a domain name. It regulates what happens if an email fails the authentication. Together with the SPF record and DKIM record, it sets strong email security.

List of DNS terms that every administrator should know

Here’s a quick rundown of the most useful DNS terms. Learning the complex structure of the Domain Name System as a beginner can be extremely frustrating. But, if we start explaining, everything will become much more straightforward and make more sense.

Domain Name System (DNS)

The Domain Name System, or DNS, is a critical component of the Internet. It’s a global naming database that converts internet domain names to IP addresses (Internet Protocol). DNS is a multi-level hierarchical system that is decentralized. Humans no longer need to remember long and complicated numbers (for example, 213.45.178.32) in order to access and explore every website thanks to this technology. Instead, visitors can type the domain name directly into their browser and go to their selected web page.

Dynamic DNS

Dynamic DNS is the second term in our list of DNS terms. Dynamic DNS (DDNS) has the advantage of automatically updating and changing the host’s IP address.

The A or AAAA DNS entries in classical DNS connect the domain name to the IP address. Dynamic DNS ensures that the user may still access the domain name even if the IP address is changed by the ISP. It is a really easy-to-use solution that also happens to be quite helpful.

Domain name

Another really important term is the domain name. It is a line of text used to map an IP address. We use it to visit websites by writing memorable and straightforward names rather than their numerical addresses, known as IP addresses. For example, instead of 213.45.178.32, we type example4domain.net. So the domain name here is example4domain.net.

IP address

The Internet Protocol (IP) uses an identifier called an IP address to name hosts on the Internet. IANA creates and assigns each IP address, which is completely unique. Furthermore, they are a prerequisite for devices to communicate and exchange information over a network. Today we divide the IP addresses into two categories: IPv4 and IPv6.

Example for IPv4 – 213.45.178.32
Example for IPv6 – 50f1:dc4:0:0:0:ffff:d52d:b220

DNS records

Let’s continue with the next term – the DNS records. They are text files that contain information about the Domain Name System. Every domain has a different amount and variety of DNS records. In addition, they represent the domain’s many entities and settings. For example, the most popular records are – SOA, A, PTR, MX, etc.

DNS query

The process of finding the IP address (an A record or an AAAA record) or different DNS records of a domain we known it as a DNS query. For example, when a customer requests information, it creates a DNS query.

DNS server

And the last important term on our list is the DNS servers. They are split into two categories: authoritative name servers and recursive name servers.

  • Authoritative name servers keep track of a particular zone’s zone file. Furthermore, they are the only ones who can respond to DNS queries. The root server, TLD server, and authoritative name server for a certain domain are examples of such servers.
  • The objective of recursive name servers is to collect the DNS query from the user and then search for the required information. To do so, these servers pass through a series of servers until they get the solution. Consider them to be the intermediary between users and authoritative name servers.

Conclusion

DNS is a multi-component system that aims to make the Internet user experience more pleasant. To sum up, you can now confidently state that you are conversant with the basic DNS terms. They are the basis upon which everything else is built.