Troubleshooting tips for DNS

Time to Live, Aging, and Scavenging

Feature	Description
Time to Live (TTL)	How long a DNS record will be valid
Aging	When records inserted into the DNS server reach expiration and are removed
Scavenging	Remove old DNS records

Time to Live – TTL depends on the type of DNS record. MX records have a longer TTL than a host A record, for example. The TTL can be modified.
Resource Record Types

Aging – DNS record removal helps to keep DNS accurate and using less disk space.

Scavenging – If DNS records have not been aged, we can force a database cleanup by removing stale records. This can be done by scavenging DNS records. Stale resource records can slow down DNS lookups and cause errors.