The NS1 Connect platform allows you to create monitoring jobs (i.e., probes) to track the health and performance of a specified device or endpoint. After creating the monitor, you can connect it to a corresponding answer within a DNS record to automatically update the answer metadata.
You can create any of the following monitor types in the NS1 Connect platform:
This article explains setting up a DNS monitor and connecting it to answer metadata using the NS1 Filter Chain. Server/device DNS monitoring tracks the availability and response time of a DNS record available from a DNS name server or resolver. This can be used to check, for example, whether or not an external public resolver is serving the correct record data back to end-users.
In the NS1 Connect platform, navigate to the Monitors page.
Click the + on the right side of the menu to launch the Create a Probe modal.
Select DNS from the drop-down list in the upper-left corner.
Under Configuration, adjust the settings as desired while considering the following:
(Required) Enter a name for the DNS monitor.
Toggle the switch to activate or deactivate the monitor. By default, this option is disabled meaning the monitor is active.
Toggle the switch to enable or disable notifications related to this monitor. By default, this option is enabled meaning notifications are active.
(Required) Select the locations from which monitoring will be executed.
Select the policy this monitor should use to determine if the monitored endpoint is down. Choose one of the following from the drop-down menu:
Quorum: The host is marked “down” if tests conducted from a majority of the monitoring regions do not pass the “up” conditions.
All: The host is marked “down” if tests conducted from all of the monitoring regions do not pass the “up” conditions.
One: The host is marked “down” if tests conducted from a single monitoring region do not pass the “up” conditions.
(Required) Enter the amount of time in seconds between each monitoring test conducted in each region. The minimum setting is 60 seconds.
Click Add Condition to define the condition(s) the hostname must meet in order to be considered "up."
First, choose the metric to validate during the test:
Response time - Average response time (in milliseconds) of DNS responses
Number of records - Number of records in the ANSWER section of the DNS response
Record RDATA - RDATA of records in the DNS response
Next, choose the comparison operator (=, <, >, etc.), and the value to compare. You can add multiple "up" conditions, just note that all conditions must be met in order for a test run to consider the host "up."
Check this box to automate a second verification test before changing the status of a host. Enabling this option can help prevent false positives.
Under DNS Settings, adjust the settings as desired while considering the following:
Enter the amount of time (in milliseconds) to wait for output after connecting. Default value is 2000 milliseconds.
(Required) Enter the domain name to be queried.
Nameserver IP or hostname
(Required) Enter the IP address (IPv4 or IPv6) or fully-qualified domain name (FQDN) of the DNS server from which to request the query domain.
Connect over IPv6
Enable this box to connect to the server specified in Nameserver IP or hostname via IPv6. If this option is disabled, IPv4 will be used.
Specify the record type of the queried domain to be requested. The default value is A.
Specify the port from which to perform the DNS query. The default value is 53.
Once complete, click Save probe. The new DNS monitor appears in your list of monitors used.
To complete the setup process, you must connect the monitor to an answer to automatically change the “up” metadata to reflect the monitor's status. When the tested host meets the “up” conditions, it will change the metadata to up=true. If the tested host does not meet the “up” conditions, the metadata is automatically changed to up=false.
Under DNS > Zones, navigate to the record upon which you want to attach the monitor. Then click into the record to view associated answers.
Click Create Filter Chain (which alternatively displays as Edit Filter Chain if filters already exist on the record).
Select or drag-and-drop the Up filter option (and any other desired filters) to the list of active filters.
Click Save filter chain when finished adding filters. Now you can see the Filter Chain configuration to the left of the answer list.
On the left-hand sidebar showing the Filter Chain configuration, click the Up filter to expand that box and reveal filter-specific metadata options.
Click the up: unset metadata label beneath the answer to view the Answer Metadata configuration screen.
Click the icon in the Feed column next to the up/down filter setting to reveal a list of available data feeds—including the monitor you created earlier.
Select the DNS monitor you created earlier, and click Ok.
Click Save record to save your changes.
When the DNS monitor detects a failed endpoint, it automatically adjusts the answer metadata to indicate that the endpoint is “down.” As a result, DNS traffic is steered to better-performing endpoints.