Foglight Experience Monitor 5.8.1 - Installation and Administration Guide

Common issues when installing the appliance

When installing a new appliance, there are two common issues that may be encountered:

For more information, see these topics:

Appliance connection failure through a web browser

This common issue occurs when the user points their web browser at the appliance and an error is returned, stating:
The page cannot be displayed.

In almost all cases, the problem is caused by incorrect entries in the appliance network settings, or the fact that the appliance is not plugged into an active switch port.

All reports are empty

If no data appears in Monitoring Reports or other reports, this may be the result of an incorrect deployment of the appliance. After the initial configuration, the system may need between five to ten minutes to collect data before it starts appearing in reports. After this period, if there is still no data, then there may be a deployment problem.

In almost all cases, the problem is caused by either incorrect configuration of the network tap, missing server IPs, and ports in the configuration.

The troubleshooting process documented in this chapter is divided into three main sections:

These troubleshooting sections are meant to be followed in the order they appear, and it is recommended that you stay with the prescribed order.

However, the type of problem you are experiencing with the appliance helps determine exactly where along the troubleshooting process you should begin. Use the following table to determine which section is the best place to start.

Regardless of which section is the start point, continue through all of the subsequent sections until the problem has been resolved. Each section will help the user to verify whether the system is working correctly or whether a configuration error has occurred.

Verify the network configuration and connectivity

During the initial configuration of the system, the network configuration may not have been set up correctly. There may also be a hardware problem with one of the network interface cards (NICs), or network cables. It is also possible that the switch port for the control NIC is inactive or has been configured incorrectly (for example, on the wrong VLAN).

These basic steps help ensure that the network configuration settings have been entered correctly.

NOTE: A Host Name value is not required for network connectivity, but you should verify it anyway.

This section assumes that the test of the previous section, Step 2: Test network connectivity, has failed. There are several common reasons for failed network connectivity. This section outlines possible reasons for this failure, and what can be done to resolve the issue.

IMPORTANT: While not explicitly stated in the following sections, the user should go back and retry the steps outlined in the previous section (Step 2: Test network connectivity) after each change made to cabling, appliance settings, or switch settings to see if the change has resolved the problem before trying a different change. Follow the instructions in that section to determine where to proceed next.

Go back and complete Step 1: Review network settings.

When a port’s link light is not on, this could be indicative of a faulty cable. Despite this, it is still possible that the link light is on even when a defective cable is being used.

Replace cables that are suspected to be defective with different cables from a system that is known to be working.

Modern switches allow a variety of settings to be changed for a switch port. Switch ports can be incorrectly configured in numerous ways:

Try connecting a second machine using the same control port cable and the same network settings. Does this second machine correctly access the network?

Connect the appliance to a switch port that was previously being used successfully by another machine. Does it work now?

This section assumes that the following results have occurred based on diagnostic actions taken in Step 2: Test network connectivity:

A DNS access verification failure may be caused by a routing issue. In most cases, the DNS server is not located on the same LAN as the appliance. This means DNS requests from the appliance must cross one or more routers to get to the DNS server. If there are routing issues, this cannot happen.

Also, if the appliance cannot access the DNS server, this typically means machines located on other segments cannot access the appliance. In this case, where the appliance is isolated to a single segment, only browsers running on client machines on the same network segment can access the appliance.

The following sections outline possible reasons for this failure, and what can be done to attempt to resolve the issue.

It is possible that the appliance is located on an isolated LAN/VLAN, which does not have access to a network with DNS servers

The appliance may be located on a LAN/VLAN that is connected to a network with DNS servers, but is also isolated behind a firewall.

Although this is not a routing issue, it does cause the Verify Access to DNS test to fail. For more information, see Step 2: Test network connectivity. This configuration is sometimes used on internal DNS servers that are hardened on extremely security conscious sites.

The Access to gateway IP test (mentioned in Step 2: Test network connectivity), tries to ping the target IP. If the target IP points to an operational machine, it is still possible that the machine is not the correct gateway for the LAN. If so, the target machine will respond to the ping, but will not be able to route requests from the appliance, leaving it isolated.

Confirm with the network administrator that the gateway IP provided is correct for the LAN segment where the appliance is attached.