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Classic Monitoring Sensors

AlertFox has 3 different Classic sensors you can create to monitor DNS, FTP, and HTTP. To create a classic sensor, select the sensor type and complete the details. When you save your new sensor, it will be shown on your Sensors page.


DNS Sensor

The DNS sensor sends a request to resolve a specific domain name to an IP address it is associated with. It measures the time it needs to resolve the IP address. It reports an error if this time is greater than the timeout value you specified or if it does not work at all. Typically a DNS query should take less than 1-2 seconds.


The DNS settings include URL to monitor, Timeout , Measurement Interval and Timezone

FTP Sensor

FTP (File Transfer Protocol) is used on the Internet for exchanging files (e.g., to upload or download files from a server). The FTP sensor monitors the FTP server’s availability and response time. It reports an error if the response time is greater than the specified timeout value or if the server does not respond at all.


The FTP settings include Hostname, Username, Password, Log in Anonymously and Passive FTP mode

HTTP Sensor

Response time is a top factor for most visitors in choosing a website. For many visitors, response time is even more important than price or content quality. The HTTP Sensor does not just ping a website, but rather monitors web page uptime and performance. It loads the complete webpage without external resources (e.g. images) and measures the load time. It reports an error if the page load time exceeds the specified timeout limits. Our Check Host tool is based on the HTTP Sensor.

The HTTP settings include URL to monitor, Timeout , Measurement Interval, Timezone, Look for Keyword and Keyword Check Mode


Keyword Check

A keyword check feature in an Http sensor ensures that the right page is displayed, not just any page. This way, you can detect error pages or defaced pages easily and distinguish them from the correct page. The HTTP sensor checks for the keyword on the website and in the page source, and triggers an alert if the keyword is (not) found. The keyword can be any word on the HTML page or in the page title. For example, if you test, a good keyword would be “AlertFox” or “Powerful”.

The keyword check feature is also useful for REST Monitoring and SOAP Monitoring.