Search This Blog

Tuesday, November 13, 2018

Splitting DNS IN TXT records over multiple lines

The individual components of a TXT record may only contain up to 255 characters each, since they're transmitted on the wire in <length><data ...> format.

Any code that's potentially expecting to take more than 255 characters SHOULD be able to coalesce multiple components into a single character array.

In master file format the braces surrounding the strings indicate that multiple components are to be included in a single TXT record - without them this would have created two separate TXT records, and the relative order of the two records would be undefined and subject to change.