DNS Lookup Test

This test emulates an 'nslookup' command to a DNS server for resolving a configured IP/host name, and reports the availability of the DNS server, the success/failure of the command, and the speed with which the server responded to the command. In practice, NsLookup reaches out over the Internet to do a DNS lookup from an authorized name server, and then formats the information returned for convenient display. Based on the statistics reported, administrators can figure out whether the DNS server is available over the network and also identify slowdowns in the responsiveness of the server.

Target of the test : Any host system

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every network interface of the target host

Configurable parameters for the test
  1. Test period - How often should the test be executed
  2. Host - The host for which the test is to be configured.

  3. DETAILED DIAGNOSIS – To make diagnosis more efficient and accurate, the eG Enterprise suite 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 server availability:

Indicates the availability of DNS Server.

 

The values for the availability of the DNS Server is provided in the table below:

Measure Value Numeric Value

Available

 1

Not Available

 0

Note:

By default, this measure can report the Measure Values mentioned above while indicating the availability of DNS Server. However, the graph of this measure is indicated using the numeric equivalents.

The detailed diagnosis for this measure provides the IP or the DNS Server Name, only when the DNS server is in available state.

DNS lookup success:

Indicates the status of the NSLookup for the server.

 

The values for the status of the NSLookup is provided in the table below:

Measure Value Numeric Value

Lookup Successful

 1

Lookup Not Successful

 0

Note:

By default, this measure can report the Measure Values mentioned above while indicating the status of the NSLookup for the server. However, the graph of this measure is indicated using the numeric equivalents.

When the value is 0 (i.e. Lookup not Successful), the detailed diagnosis for this measure provides the reason for the NSLookup failure.

DNS lookup time:

Indicates the response time of the NSLookup.

Seconds

Ideally, the value of this measure should be low.