Network Test

This test monitors the network connectivity from an external location (e.g., the eG server) to a host system.

Target of the test : A host system

Agent deploying the test : An external agent

Outputs of the test : One set of outputs for every target host being monitored

Parameter	Description
Test Period	How often should the test be executed
Host	The host for which the test is to be configured.
Targets	In the TARGETS text box, specify a comma-separated list of name:IP address pairs. While the name is just a display name, the IP address refers to the IP to be monitored. This specification will ensure that the test pings multiple IP addresses. For example - mysql:192.168.0.102,egwebsite:209.15.165.127
Packetsize	Specify the size of packets used by the test in bytes.
Packetcount	The number of packets to be transmitted during the test.
Timeout	How long after transmission should a packet be deemed lost (in seconds).
PacketInterval	Represents the interval (in milliseconds) between successive packet transmissions during the execution of the network test for a specific target.
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
Avg network delay	Indicates the average delay between transmission of packet to a target and receipt of the response to the packet at the source.	Secs	An increase in the value of this measure is a cause for concern. Given below are some common reasons for such an anomaly: The network between the target device/server and the eG external agent is congested. When there is an increase in traffic on the interconnecting network, data transmission can slow down data transmission, thereby increasing communication latency. The quality of the network connection between the eG external agent and the target device/server is sub-par. Poor signal quality, faulty transmission lines, etc. can result in an increase in packet loss and/or network latency. The target device/server is overloaded. If the target is very busy, it takes longer to respond to requests, and this will result in an increase in latency. There are problems with network routing between the target device/server and the eG external agent . A faulty network router, routing loops, etc., can increase network latency. Check the detailed diagnosis of this test to track latency on the first three hops between the agent and the target device/server. The latency to each hop can be used to determine which hop the problem lies in.
Min network delay	The minimum time between transmission of a packet and receipt of the response back.	Secs	A significant increase in the minimum round-trip time is often a sure sign of network congestion.
Packet loss	Indicates the percentage of packets lost during transmission from source to target and back.	Percent	An increase in the value of this measure is a cause for concern. Given below are some common reasons for such an anomaly: The network between the target device/server and the eG external agent is congested. When there is an increase in traffic on the interconnecting network, packets may be dropped. The quality of the network connection between the eG external agent and the target device/server is sub-par. Poor signal quality, faulty transmission lines, etc. can result in an increase in packet loss and/or network latency. The target device/server is overloaded. If the target is very busy, it takes longer to respond to requests, and this will result in packet drops. There are problems with network routing between the target device/server and the eG external agent . A faulty network router, routing loops, etc., can increase packet loss. Check the detailed diagnosis of this test to know the hops that are on the path from the external agent to the target device/server, and the packet loss on each hop. This information can be used to diagnose the hop(s) that could be causing excessive packet loss.
Network availability	Indicates whether the network connection is available or not	Percent	A value of 100 indicates that the system is connected. The value 0 indicates that the system is not connected. Typically, the value 100 corresponds to a Packet loss of 0. The value 0 for this measure could mean that the target device/server is either down or too busy, or the interconnecting network is down.
DNS resolution	Indicates whether/not the Hostname is successfully translated into its corresponding IP address.	Percent	The value 100 for this measure could mean that the host name has been successfully translated into its corresponding IP address without any errors. The value 0 for this measure could mean that the process of translating the host name into IP address has completely failed.

Note:

If the Network test is executed by a Linux agent, then this agent will not be able to collect the detailed measures (i.e., detailed diagnosis) for the Network test. To resolve this issue, do the following:

Login to the eG manager and edit the eg_tests.ini file (in the /opt/egurkha/manager/config directory) on it.
By default, the MaxHopsForNetworkTestDD parameter in the [agent_settings] section of the file is set to 3. Change this to 16 instead and save the file.