TTL for PTR records on Windows 2003 Server DNS

Question

When I look at the TTL (Time to Live) for PTR records (Reverse Lookup Zone) on one of our Windows 2003 DNS servers I see some are at 15 minutes, others are at 20. They have "Delete this record when it becomes stale" checked.

• These PTR records are for workstations that get IPs from Windows DHCP, so I think that creates the PTR records dynamically?
• How is TTL for these records set?

Answer 1

Workstations (Windows 2000, XP, and above) in a domain will register themselves in DNS. They will create an A record and a PTR record. A DHCP server can also be configured to created records on the behalf of older clients.

You can control the behavior including the TTL via group policy.

See:

• http://support.microsoft.com/kb/294785
• http://support.microsoft.com/kb/816592