Configuring a DNS Test

This section describes how to detect the speed at which a DNS name is resolved to an IP address using a DNS test.

Context

A DNS test is based on UDP packets. Only one probe packet is sent in one DNS test to detect the speed at which a DNS name is resolved to an IP address. The test result clearly reflects the performance of the DNS protocol on the network.

Procedure

Run system-view
The system view is displayed.
Run dns resolve
Dynamic DNS is enabled.
Run dns server ip-address [ vpn-instance vpn-name ]
An IP address is configured for the DNS server.
Run dns server source-ip ipv4Addr
The IP address of the local DNS client is configured as the source address for DNS communication.
Create an NQA test instance and set the test instance type to DNS.
1. Run nqa test-instance admin-name test-name
  An NQA test instance is created and the view of the test instance is displayed.
2. Run test-type dns
  The test instance type is set to DNS.
3. (Optional) Run description description
  The description is configured for the test instance.
Run dns-server ipv4 ip-address
An IP address is configured for the DNS server in the DNS test instance.
Run destination-address url urlValue
A destination URL is specified for the NQA test instance.
(Optional) Set optional parameters for the test instance and simulate packets transmitted on an actual network.
1. Run agetime ageTimeValue
  The aging time is set for the NQA test instance.
2. Run source-address ipv4 srcAddress
  A source IP address is configured for the probe packet.
(Optional) Configure test failure conditions.
Run timeout time

A timeout period is configured for a response packet.
(Optional) Configure NQA statistics collection.
Run records { history number | result number }

The maximum numbers of historical records and result records are set for the test instance.
(Optional) Enable the system to send traps to the NMS.
1. Run test-failtimes failTimes
  The function that traps are sent to the NMS after the number of continuous test failures reaches a certain value is configured.
2. Run threshold rtd thresholdRtd
  An RTD threshold is set.
3. Run send-trap { all | [ rtd | testfailure | probefailure | testcomplete ]^* }
  A condition for triggering a trap is configured.
(Optional) Run vpn-instance vpn-instance-name
A VPN instance name is configured for the test instance.
Schedule the NQA test instance.
1. (Optional) Run frequency frequencyValue
  A test interval is set for the test instance.
2. Run start
  The NQA test is started.
  
  You can start an NQA test instance immediately, at a specified time, after a delay, or periodically.
  - To start an NQA test instance immediately, run the start now [ end { at [ yyyy/mm/dd ] hh:mm:ss | delay { seconds second | hh:mm:ss } | lifetime { seconds second | hh:mm:ss } } ] command.
  - To start an NQA test instance at a specified time, run the start at [ yyyy/mm/dd ] hh:mm:ss [ end { at [ yyyy/mm/dd ] hh:mm:ss | delay { seconds second | hh:mm:ss } | lifetime { seconds second | hh:mm:ss } } ] command.
  - To start an NQA test instance after a specified delay, run the start delay { seconds second | hh:mm:ss } [ end { at [ yyyy/mm/dd ] hh:mm:ss | delay { seconds second | hh:mm:ss } | lifetime { seconds second | hh:mm:ss } } ] command.
  - To start an NQA test instance at a specified time every day, run the start daily hh:mm:ss to hh:mm:ss [ begin yyyy/mm/dd ] [ end yyyy/mm/dd ] command.
Run commit
The configuration is committed.