Thursday, November 3, 2011

Troubleshooting tips for DNS

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