Overview

Use the DNS Event Monitor to make sure name resolution is working correctly. DNS (domain name resolution) is the protocol that is used to translate host names like "www.frameflow.com" into IP addresses like 54.84.4.210. When things go wrong with DNS, network functionality starts to degrade quickly. It's often a good idea to have DNS event monitors running regularly to verify that well-known external host names (like www.google.com) are being resolved and as host names for important internal systems.

Use Cases

• Ensuring name resolution services are operational
• Getting alerts about changes in name resolution

Monitoring Options

This event monitor provides the following options:

Resolve Name Using

The DNS event monitor can automatically detect the DNS server(s) that have been assigned to your FrameFlow system and use them for its checks. Or you can tell the event monitor to use a specific DNS server that you want to test.

Alert with [Info/Warning/Error/Critical] if the DNS server is unreachable

Use this option to get alerts if the DNS server could not be contacted.

Alert with [Info/Warning/Error/Critical] if the device name cannot be resolved to an IP address

With this option selected, the event monitor will alert you if it was able to contact the selected DNS server but the server was unable to resolve the hostnames of the network devices you selected.

Alert with [Info/Warning/Error/Critical] if the IP address changes

With this option selected, the event monitor will remember the IP address it got on the previous run and will compare it with what it gets on the current run. If they are not the same then the event monitor will alert you with the selected event status. This option is great for detecting accidental changes to DNS records; however, it is not recommended for situations where round-robin DNS is configured. In round-robin DNS environments, the host name is intentionally resolved to different addresses on each run to provide a form of load balancing.

Authentication and Security

This event monitor does not require authentication.

Protocols

Data Points

This event monitor generates the following data points:

Data Point	Description
Time to Resolve (milliseconds)	The time it takes for the event monitor to resolve the DNS name.

Sample Output

Tutorial

To view the tutorial for this event monitor, click here.