For business reasons, website users prefer to use custom nameservers showing their own brand name.

At times, improper setup of nameservers cause problems with website showing up in the browser. And, a detailed DNS check will show errors like “No valid SOA record came back.”

As part of our Server Administration Services, we correct such DNS settings in customers’ servers.

Today, we’ll see how our Dedicated Engineers fixed the SOA record missing error for one of our customers and made website working.

More details on the error

Before we dig deeper, let’s take a look at the scenario of the error.

The help-desk request from the customer said:

I’ve pointed my new domain to my nameservers, but it’s been 72 hours and it still does not resolve. Is there something wrong on the server? FYI, there is a wordpress install at the root, so that should come up.

The customer’s newly added WordPress website was not showing up in the browser. Additionally, a DNS report check of the domain reported the error as:

What is SOA record?

Basically, Start of Authority record aka SOA record  contain many details about the DNS records of the domain. The SOA record of a domain include details like DNS modification time, DNS update interval, DNS admin email address and so on. And, a zone file can contain only one SOA record.

Since DNS works in a group of servers called cluster, records within each cluster need synchronization through zone transfers. And, it is the SOA record that control this zone transfer among DNS servers. As a result, a faulty SOA record will cause problems with website.

Causes for missing SOA record

Now, it’s time to see the major reasons for missing SOA record. From our experience in managing servers, we see broken SOA record due to:

1. Incorrect name server glue records

For custom nameservers to work properly, it should have proper glue records. These glue records need to be set up at the domain registrar side. Each custom nameserver need proper record pointing to its IP address. Missing glue records always result in DNS zone lookup failure.

2. Missing dns records for nameserver

Similarly, some users just set up the Glue records for nameservers, but fail to add necessary A records for nameservers.

By default, SOA record should point to a DNS name. Then, it need an A record with the DNS name of the dns server to resolve to.

The basic format will be:

domain.com SOA ns.domain.com
domain.com SOA ns2.domain.com
ns.domain.com      A    XXX.XXX.XXX.XXX

If for any reason, when nameservers fail to resolve, it results in missing valid SOA record error.

3. DNS server connectivity problems

Yet another reason for “No valid SOA record came back” error attributes to DNS server connectivity problems. Even when the details in the dns record are all correct, when the server as such do not respond, dns zone requests fail. As a result, the website will not show up in the browser too.

How we corrected SOA record

We’ll now see how our Dedicated Engineers traced the root cause of the error and fix it. It involved a series of steps like:

1. Finding the point of failure

The first step in fixing any DNS problem lies in understanding the point of failure. And, for that the ‘dig‘ command proves helpful.

A simple dig command of the domain showed broken A records for the nameservers of the domain.

domain.net. 172800 IN NS ns1.domain.com.
domain.net. 172800 IN NS ns2.domain.com.
dig: couldn't get address for 'ns1.domain.com': no more

The dig command clearly reported that it cannot get the address of the name server.

2. Verifying DNS records

To find the reason for address failure, we then checked the Glue records of the nameservers. And, we found that they were correct. Unfortunately, the dns record did not have entries for ns1 and ns2. Hence the dig command of the domain resulted in the error:

;; Connection to 2001:xxx:7xx::30#53(2001:xxx:7xx::30) for xxxx.net failed: network unreachable

3. Fixing DNS

To fix the problem, we added A records for both ns1 and ns2 in the zone record of the nameserver. The nameserver domain was using Cloudflare for its DNS. So, our Support Engineers made the necessary changes from the Cloudflare portal.

After setting the dns, we asked the customer to wait for the DNS changes to propagate. Once the propagation time was over, domain started resolving correctly. And, the DNS report did not show any further errors.

[Experiencing dns problems with websites? Our experts can fix it for you.]

Conclusion

Precisely, “No valid SOA record came back” error happens due to missing glue records or invalid dns records for nameservers, DNS server connectivity problems, etc. Today, we saw how our Support Engineers fixed the SOA error for one of our customer and made his website working.