DNS Security Best Practices to Secure Your DNS Server (Checklist)

DNS Security Best Practices to Secure Your DNS Server (Checklist). The Internet has become integral to our lives as it has opened the doors to information like never before. But it also opened doors to look or steal valuable data. DNS security best practices are vital for all organizations since the service has become critical to almost all operations involving networked applications. It facilitates the communication of networked applications. 

What is DNS Security?

Firstly it is reported that Domain Name System or DNS attacks have been on the rise as businesses have started adopting hybrid cloud or remote work cultures due to the pandemic. The DNS serves as a reference point for other sites and searchers. The address typed in the address bar is the domain name, an example can be espnsports.com or google.com. The DNS helps makes IP search easy.

Secondly DNS was designed with no regard to cyberattacks, which led DNS servers vulnerable to access the IP address of the business server. A study conducted by EfficientIP and IDC found that 87% of the interviewed organizations across the world were subject to DNS attacks, with each attack costing nearly one million USD.

Thirdly the security issue is on the rise, so you must leverage all the resources you can to protect your DNS infrastructure from any potential attack.

DNS security is about monitoring and mainaining

Monitor DNS activity to indicate that security issues in your network.

Maintain your DNS availability and health.

DNS Security Components

Automation.

Security and Threat Intelligence. 

Security Control.

Deployment of DNSSEC, DoT or DoH.

Analytics and Reporting .

If you are looking for the best practices to prevent DNS attacks, here are the most effective practices in 2022 for DNS Security Best Practices to Secure Your DNS Server.

DNS Security 13 Best Practices

DNS security should be considered an essential part of any business’s security plan. Name resolution services (translating hostnames into IP addresses) are used by nearly all applications and services on a network.

1. Log all DNS activities

First point is enabling log information for DNS activities. This is one of the most preferred and advised practices businesses can use to safeguard their DNS server from attackers. It is an effective strategy that provides comprehensive details of DNS events and activities.

Businesses can also drive valuable insights into whether there is any attempt by hackers to access the server or compromise it. This is also monitored by ethical hackers to prevent any breaches in server security.

In addition, DNS logs can also reveal any attempts to cache poisoning, which attackers use to redirect users to malicious websites by replacing the site’s original IP with a malicious website’s IP.

Although DNS logs may compromise the performance, administrators must never disable them as it would lead to DDoS attacks and serious ramifications.

2. Keep the DNS cache locked

When the DNS server carries out a query, it usually caches the data for future reference to return the query quickly the next time. However, there is a danger associated with DNS caching as attackers can alter the details cached.

The best way to prevent unauthorized altering of cached data is to lock the detail from unsanctioned access.

Locking the cache is one of the most widely practiced ways to protect the DNS server from attackers. It enables the administrators to decide when the cached data needs to be scrutinized and updated. With this, the DNS server stores only the lookup information for a specific period of time as marked in the time to live.

Importantly, what makes this one of the most used practices for DNS security is that it offers 100% security against cache poisoning.

3. Configure access control lists (ACL) precisely

One of the most effective practices to protect primary DNS servers from attacks is to control the access to the same with a well configured Access Control List. It is important to limit the access to the primary DNS server to the IT and system administrators.

Configuring and maintaining an access control list guarantees that only a permitted set of clients can communicate with the primary DNS server. Apart from this, the list must also configure what servers are authorized for zone transfers. Attackers might use secondary DNS servers to push zone transfer queries with the goal of getting into the server.

With an adequately defined ACL and zone transfer allocation, you can thwart cybercriminals’ attempts to grab zone information or data.

4. Isolate authoritative from recursive name servers

Importantly here, when a query is initiated, an Authoritative Server starts a lookup for a local database to find a name and the IP associated with the name. On the other hand, Recursive Servers look for the local database in addition to additional name servers to find a name and the associated IP.

Businesses must isolate these two servers from each other based on the logical views of the network in operation to protect the integrity of the server.

Finally the network administrators must ensure that only the authoritative name servers are configured to send updates to the DNS server.

5. Constantly update the DNS server

Every DNS server provider publishes multiple security updates and patches every year. As a business that wants to stay secure from cyberattacks, you must update your server whenever a new one is available.

Most of the time, attackers take advantage of security vulnerabilities in the DNS server program to gain access to the same.

Although it can be challenging for most businesses to ensure timely updates of servers, having a centrally managed server system is the key. In addition, you must also look for any updates released as most server programs are not configured to warn for outdated versions.

6. Deploy dedicated DNS applications

Using custom made DNS applications is another practice to keep the attackers at bay. Dedicated DNS software and hardware can offer a multitude of advantages to businesses on both performance and security fronts.

Customized DNS applications can be updated in any way deemed necessary by the organization from its RAM, driver requirements, source ports, network interface and protocols.

What’s important is that dedicated servers ensure that many security protocols and functionalities can be enabled in the server, making it extremely hard to penetrate and compromise.

7. Validate DNS data integrity with DNSSEC

It is important to point out that businesses can use Domain Name System Security Extensions or DNSSEC to evaluate the queries and send only those validated for authenticity. The DNSSEC, another security check layer, digitally signs the DNS data communicated to warrant its integrity.

When the DNSSEC is installed, the DNS server scrutinizes the requests for a valid signature from the DNSSEC. Only when the signature is identified and validated.

Companies can protect their DNS servers from DNS spoofing and cache poisoning by integrating DNSSEC as it provides integrity of shared data and its origin.

8. Mask the primary DNS server and information

It is important job for system administrators to mask the organization’s primary DNS server from the public. Stealth or masked master name servers do not store name server details in the DNS databases that can be publicly accessed.

In addition having slave and master servers makes it easier for the organization to protect the primary server as the users cannot access it.

Further, the slave servers are also protected as only the master server can alter it with designated push commands.

9. Time limit the recursive DNS query response

Response rate limiting is another practice that you must leverage to protect your DNS server from crashing or being attacked. Limiting responses to a specific IP with multiple queries can effectively thwart DDoS attacks as multiple queries will take a longer time for the server to respond.

Unfortunately this makes the name server resistant to DDoS attacks as the attacker may not get the response they need to crash the server. Most leading name server providers, such as Knot, Bind 9.6.4 or higher, and NSD offer response rate liming options as part of their server configuration.

10. Facilitate random DNS socket pool utilization

During DNS lookups, a DNS socket pool allows the server to choose a random source port from a collection of idle ports. Therefore, the server would choose different sockets for different operations, making it difficult for attackers to guess the port that the server opts for with source port DNS queries.

Ultimately, this can render the DNS server even more insulated from the attacks of malicious parties.

11. Ensure DNS availability with adept redundancy

Importantly, the unavailability of the DNS can negatively impact the user experience and tarnish the reputation of your business while giving access for malicious entities to crawl into your system unnoticed.

This is where adequate DNS redundancy must be assured by deploying multiple DNS servers adjacent to the primary server.

In case of DDoS attacks, your business can still function from the secondary or tertiary servers in place.

DNS redundancy would not only assure continued service delivery but also mitigate the repercussions of any attacks.

12. Reinforce the name servers

Remember your name server is integral to your network’s performance and security. Any compromise on its security can endanger the entire server and network.

As such, you must only use the name server computers to run the server program, and the OS needed to do that.

Installing software programs and solutions that do not support the primary functioning of the name servers is akin to inviting trouble.
Apart from this, there is also the issue of performance.

Additional programs would silo the computing power of the name server and cause the same to lag or initiate attacks if bugs or viruses are present.

13. Use Active Directory Integrated Zones

 Why not use Active Directory integrated zones. You can only use AD integrated zones if you have DNS configured on your domain controllers. It will lead to following benefits:

 

A) Replication: AD integrated zones store data in the AD database as container objects to get automatically replicated to other domain controllers


B) Redundancy: prevents a single point of failure for DNS. If one DNS server fails the other server has a full copy of the DNS information.

 

C) Simplicity: AD Integrated zones automatically update without the need to configure zone transfers. 


D) Security: with this feature only authorized clients and members of the DNS domain can update their records in DNS zones. Other users will be denied a requests from the computers not part of the domain.

DNS Security Tips

  1. Secure DNS forwarders.
  2. Filter DNS Requests .
  3. DNS Socket Pool.
  4. DNS Cache Locking.
  5. DNSSec Filter DNS Requests.

DNS Security Best Practices to Secure Your DNS Server (Checklist) Conclusion

Monitoring for differences in DNS changes, account location, first-time use, accessing sensitive data, and activity outside of working hours are only a few metrics that can be correlated to painting a broader picture of detection.

Although most of these DNS practices are not overly cost efficiency for businesses, they can help you shield your business and users from cyberattacks. If you do not have a current strategy for DNS protection, you must devise one as quickly as possible.

It can protect your network and applications from any potential attacks and save your brand’s image in the eyes of the public. What do you do in your organization to protect your DNS? What is the best practice that you use?

Avatar for Hitesh Jethva
Hitesh Jethva

I am a fan of open source technology and have more than 10 years of experience working with Linux and Open Source technologies. I am one of the Linux technical writers for Cloud Infrastructure Services.

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