A recommended TTL (Time to Live) value to enable DNSSEC (Domain Name System Security Extensions) is indeed less than 3 days. The TTL value is significant in the context of DNS because it dictates how long DNS resolvers are allowed to cache DNS records before querying the authoritative DNS server for an update.
In the case of DNSSEC, having a shorter TTL can help ensure that changes in DNS records due to key rollovers or security updates are propagated more quickly across the internet. This is crucial for maintaining security and integrity, as DNSSEC relies on cryptographic signatures to validate the authenticity of DNS responses. A TTL that is less than 3 days is generally considered optimal for environments where rapid updates or security measures are required.
Setting a longer TTL could delay the propagation of critical updates, and in the context of security, this could potentially leave a domain vulnerable if changes are needed. Therefore, while values shorter than typically recommended (like 1 hour or 3 hours) can be beneficial in more dynamic environments, keeping it at less than 3 days strikes a balance between allowing for timely updates and maintaining efficient caching.