Hosts File Check Test

This test monitors the name resolution behavior of the system by checking whether domain names are resolved accurately by both local host files and external DNS servers. It ensures the DNS availability and measures the DNS response time to detect potential availability and latency issues in DNS resolution. Furthermore, this test monitors any recent modifications made to the host file. This could help in identifying any unauthorized changes that can impact the resolution process. This way, the test helps in early detection of connectivity issues and thereby helps administrators to carry out troubleshooting at the earliest.

Target of the test : Any host system

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every host system being monitored.

Configurable parameters for the test
Parameter	Description
Test Period	How often should the test be executed.
Host	The host for which the test is to be configured.
Show DNS Info	By default, this parameter is set to No. To enable reporting of DNS availability and DNS response time metrics, set this parameter to Yes.
DD Frequency	Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD frequency.
Detailed Diagnosis	To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option. The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled: The eG manager license should allow the detailed diagnosis capability Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.

Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

DNS availability

Indicates whether a successful response is received from the DNS server in response to the emulated user request.

Percent

This measure is reported only when the Show DNS Info parameter is set to Yes.

An availability problem can be caused by different factors – e.g., the server process may not be up, a network problem may exist, or there could be a configuration problem with DNS.

DNS response time

Indicates the time taken by DNS server to respond to a request.

Seconds

This measure is reported only when the Show DNS Info parameter is set to Yes.

An increase in response time can be caused by several factors such as a server bottleneck, a configuration problem with DNS, a network problem, etc.

Is hosts file modified recently?

Indicates whether or not the hosts file has been modified recently.

The values that this measure can report and its corresponding numeric equivalents are listed in the table below:

Measure Value	Numeric Value
No	0
Yes	1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate whether the host file was modified. In the graph of this measure however, the same is represented using the corresponding numeric equivalents only.

If the value of this measure is Yes, then use the detailed diagnosis to find the modification.