VM Connectivity Test

Sometimes, a VM could be in a powered-on state, but the failure of the VM operating system or any fatal error in VM operations could have rendered the VM inaccessible to users. In order to enable administrators to promptly detect such ‘hidden’ anomalies, the eG agent periodically runs a connectivity check on each VM using the VM Connectivity test, and reports whether the VM is accessible over the network or not.

Target of the test : A Hyper-V / Hyper-V VDI server

Agent executing the test : An external agent

Output of the test : One set of results for each VM configured on the Hyper-V host being monitored

Configurable parameters for the test
Parameter Description

Test period

This indicates how often should the test be executed.

Host

Specify the HOST for which this test is to be configured.

Port

Specify the port at which the target host is listening. By default, this is NULL

Packet Size

The size of packets used for the test (in bytes)

Packet Count

The number of packets exchanged between the virtual desktop and the user terminal during the test

Timeout

How long after transmission should a packet be deemed lost (in seconds)

Packet Interval

Represents the interval (in milliseconds) between successive packet transmissions during the execution of this test.

Report Unavailability

By default, this flag is set to No. This implies that, by default, the test will not report the unavailability of network connection between a user terminal and a virtual desktop. In other words, if the Packet loss measure of this test registers the value 100% for any user, then, by default, this test will not report any measure for that user; under such circumstances, the corresponding user name will not appear as a descriptor of this test. You can set this flag to Yes, if you want the test to report and alert you to the unavailability of network connection between a user terminal and a virtual desktop. 

Measurements made by the test

Measurement Description Measurement Unit Interpretation

Avg network delay:

Indicates the average delay between transmission of packet to a VM 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 VM and the eG external agent is congested. When there is an increase in traffic on the interconnecting network, data transmission can slow down, thereby increasing communication latency.

  • The quality of the network connection between the eG external agent and the VM is sub-par. Poor signal quality, faulty transmission lines, etc. can result in an increase in packet loss and/or network latency.

  • The VM is overloaded. If the VM is very busy, it takes longer to respond to requests, and this will result in an increase in latency.

  • There are problems with network routingbetween the VM 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 VM. 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

A value close to 100% for this measure is a cause for concern. Given below are some common reasons for such an anomaly:

  • The network between the VM 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 VM is sub-par. Poor signal quality, faulty transmission lines, etc. can result in an increase in packet loss and/or network latency.

  • The VM is overloaded. If the VM is very busy, it takes longer to respond to requests, and this will result in packet drops.

  • There are problems with network routingbetween the VM 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 target VM, 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 of VM:

Indicates whether the network connection is available or not.

Percent

A value of 100 indicates that the VM is connected. The value 0 indicates that the VM 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 VM is either down or too busy, or the interconnecting network is down.