Client caches may cause confusion during updates. Many DNS clients check for DNS updates very infrequently and might not reflect DNS changes for hours or days. Manual steps may be needed to trigger immediate updates. Details for controls of cache and update vary for different DNS clients and DNS servers, but DNS caching and update propagation delays are significant factors and implementations have mechanisms to manage these issues.
DNS Server failure management should be considered. Redundant servers and fallback host files are examples of possible error management tools.