SOA Serial Number Invalid Format and Expire Value Issues


When I checked the DNS health of my domain in MXToolBox’s DNS Lookup tool, it noted the following two problems:

  1. SOA Serial Number Format is invalid
  2. SOA Expire Value out of recommended range

Since Cloudflare apparently sets these values, who am I to believe?

Thanks in advance for any replies.

Welcome to the Cloudflare Community. :logodrop:

Given the sheer volume of Cloudflare hosted DNS that operates without issue, you can safely ignore those erroneous results from MXToolbox. You can easily confirmt hat your serial is valid by comparing it with the requirements.

The SOA serial number is defined in RFC 1982.

7. The DNS SOA serial number
The serial number in the DNS SOA Resource Record is a Serial Number as defined above, with SERIAL_BITS being 32. That is, the serial number is a non negative integer with values taken from the range [0 … 4294967295]. That is, a 32 bit unsigned integer.

MXToolbox also chooses to display a warning if the EXPIRE value isn’t in a range recommended by RFC 1912. A recommendation is not a requirement, so that too can be safely ignored.

Thanks for the quick response, @epic_network. I thought as much, but wasn’t sure. Cheers.

1 Like