What is a DNS SOA Record?

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DNS SOA record contains information related to your domain. SPF also depends on DNS SOA, hence it’s vital for email protection.

by Ahona Rudra

Reading Time: 6 min
What is a DNS SOA Record?
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Although the exact number of active websites keeps changing, on average, 175 new websites are created every minute! This translates into 252,000 new websites each day. Needless to say, users have to enter a website’s URL to reach the desired page; this is where the role of the DNS SOA record begins. 

We’ve already discussed what is a DNS record and its types previously. In this post, you’ll know what is a DNS SOA record. Keep reading till the end to know its importance, structure, procedure, and more. 

Key Takeaways

  1. A DNS SOA record is essential for aligning with IETF standards and ensuring successful zone transfers between primary and secondary servers.
  2. SOA records contain vital information such as the primary name server, the administrator’s email address, and refresh and expire times.
  3. Proper configuration of the SOA record helps prevent compliance issues and ensures the integrity of DNS zones.
  4. Zone transfers, facilitated by SOA records, allow content replication across multiple servers, saving time and improving efficiency.
  5. Utilizing tools to check SOA records can help troubleshoot potential issues and ensure that DNS information is accurate and up to date.

What is a DNS SOA Record?

SOA record or Start of Authority record is a type of DNS record containing crucial information like the administrator’s email address, refreshing server timeframe, domain updating history, etc. Configuring an SOA record in your respective DNS is important to align with the IETF (Internet and Engineering Task Force) standards. 

DNS SOA records are needed for successful zone transfers as you’ve to send them from a primary server to a secondary server. 

What is Included in a Typical DNS SOA Record?

A standard DNS SOA record will include the following details:

  • Primary name server of a domain.
  • Correspondence of the responsible party of a domain.
  • A timestamp to capture all the updates made.
  • The number of seconds left for zone refreshment.
  • The number of seconds left for discarding a failed refresh.
  • The upper limit in seconds before a zone is labeled as inauthoritative.
  • The negative result TTL or Time-to-Live. TTL is the amount of time that a packet or data survives for. 

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Why Do You Need an SOA Record?

A DNS SOA record holds details about your zone. DNS name servers are usually set up in clusters, and the database is synchronized using internal zone transfers. Any zone without an SOA record fails to comply with IETF’s protocols, and zone transfer isn’t possible. Thus IT-driven business owners must know what is a DNS SOA record.

What is Zone Transfer in DNS?

To understand how SOA records work, you must know what zone transfer is in DNS. 

Zone transfer is the process of replicating any zone’s content on a primary server across DNS servers. This eliminates the need to edit information on multiple servers. So, you can edit information on the main server and copy it to others, saving time and effort. 

How Do SOA Records Work?

DNS is a decentralized system working as per a hierarchy. So, name servers supply information to the servers dedicated to a particular zone by administering all the zone files. These are simple text files containing details regarding all the DNS records. These records offer information on the number of issues, like if the right server has been requested to resolute a responsibility or not. 

DNS SOA records are necessary for server clusters as they distribute requests among devices. This averts the overloading of a specific server that may lead to system failure.

A zone transfer must be performed regularly for zone files to remain active on all the involved servers. However, slaves (servers situated lower on the hierarchy) must be contemporized with the master server (the single host in a particular domain that maintains the authoritative maps).

It directs how a zone transfer should be carried out and regulated. Thus, a DNS SOA record receives all types of information.

SOA Record Structure

Now that you know what is a DNS SOA record, it’s time to know a bit about its structure.

As already stated, a DNS SOA record has vital information related to a specific DNS zone or domain. This record is aligned in an organized manner that is easily comprehended by servers and browsers. Here’s what is included in a standard SOA record structure:

Serial Number

It’s the revision number of a zone file, which changes every time a file changes. This value should be changed so that changes made will be distributed across all DNS servers. In most systems, this process is automatic.

Primary Name Server

As the name says, it’s the primary DNS server of a zone. It changes back to the default one if you enter an invalid primary name server.

DNS Admin Email

It’s the email address of the person responsible for administering particular DNS and zone files. If you enter the wrong email address, it changes back to the default one.

Refresh Rate

Refresh rate is the time in seconds for which a secondary server waits before querying the primary DNS SOA record for updates. The refresh rate varies from 1200 to 43,200 seconds.

Retry Rate

Retry rate is the time in seconds for which a secondary server waits before retrying a failed zone transfer. Typically, the refresh rate is more than the retry rate, and the default rate is 1800 seconds. However, it can vary between 180 and 2,419,200 seconds. 

Expire Time

It’s the time in seconds that a secondary server tries to finish a zone transfer. If this time expires before the completion of a zone transfer, its zone files will also be expired. The secondary server won’t respond to queries as it perceives the data to be old. The default expiration time is 1,209,600 seconds.

Default TTL

TTL stands for Time-to-Live, which is the time period for which a packet or data lives for. Other servers use this value to know how long they should keep the data in the cache. The default value is 3,600 seconds or 1 hour.

SOA Record Check

You can use special tools or web services to check your website’s DNS SOA record. All you need to do is enter a relevant domain, and the following page will display the ‘A’ record. You can select ‘SOA’ in the appropriate field to check records. 

Public DNS allows you even to establish additional efficient connections with DNS; however, only limited resources offer this. The information received via DNS flows from the originator, and the security protocols can’t be manipulated theoretically. 

This type of SOA record check request is performed using the ‘Question and Answer’ format. You can seek the master server, the admin’s email address, and the time specifications. 

You can verify your SOA record using our SOA record lookup tool when you sign up on the PowerDMARC platform. The process is instantaneous and accurate, with results that highlight errors in your record, helping you troubleshoot issues faster! 

Final Thoughts

DNS SOA record contains sensitive information like an administrator’s email address, server refreshing timeframe, domain update history, etc. These records help in zone transfer, the process of copying any zone’s content across all the secondary DNS servers. This saves time and effort in manually replicating content. SOA records distribute requests among various servers to avoid congestion and breakdown. 

Infotech-driven businesses must comply with a DMARC policy that works based on SPF and DKIM protocols. You’ve to publish a DMARC record in the DNS to instruct recipients’ mailboxes on how to deal with your emails per the policies set. You can use the DMARC analyzer to gain insights on several issues related to it.

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