PRTG Manual: Ping/Latency Monitor
The Ping/Latency monitor allows you to monitor the Ping response time of a device. When a Ping monitor runs it sends a ping request to the device and compares the response time to the monitors specified thresholds.
The Ping monitor editor contains the following tabs that require configuration: Settings, Devices, Schedule, Event, and History.
The Schedule, Events and History settings are the same for all monitor types. See Configuring Monitors for more information about configuring these settings. For the other tabs see the information below.
Name
The Monitor name is the name of the monitor used to refer to the monitor in the monitors list view, and in monitor events and notifications. Monitor names must not be unique but it is recommended you use unique names to differentiate them.
Response Test(s)
The latency tests can be performed using either Ping, or SNMP responses or both. If both are selected the devices must respond to both Ping and SNMP requests for the monitor to remain in an up state. If SNMP is used you can also specify whether to check the system up time of the device. If the System up time appears to have reset since the last query the state of that device will be considered in an "Information" state for the current request. (Meant not to alarm; but provide information that can be used for troubling shooting.)
Note: SNMP requests require the device have valid SNMP credentials associated with them. See Managing Device Credentials for more information.
Ping /ICMP Settings
The Ping/ICMP settings specifies the timeout in milliseconds and the number of retries to be performed for each ping request. If the device responds to the ping request within the specified timeout and retries the request will be considered valid.
Use Round-Trip Time
Use Round-Trip time specifies whether to use the response time as a threshold for determining the monitor state. If the response time exceeds the critical or warning response time a down or warning state occurs respectively. The warning time must be less than or equal to the critical time.
The devices tab allows you to select which devices will be monitored. To add devices to the monitor select the 
button in the lower left corner. A device selector will be presented allowing you to choose one or more devices to monitor. To remove a device from the monitor select it in the grid and press the delete button 
.
By default, the main IP address of the device is selected as the IP address to Ping. Nevertheless, optional IP addresses can be added by selecting the device in the grid and selecting the edit button 
. Also, any Ping monitor can be configured to resolve a defined "Hostname" before sending the ping requests. To edit these settings, press the edit button 
.
