| Event Id | 503 |
| Source | DNS |
| Description | DNS Server secondary zone %1, had no master IP addresses in registry. Secondary zones require masters |
| Event Information | Explanation: Registry Boot problem |
| Reference Links | DNS Event IDs 1 Through 1657 for Windows NT 4.0 SP4 |
Catch threats immediately
We work side-by-side with you to rapidly detect cyberthreats
and thwart attacks before they cause damage.