The Diagnostic feature of GEM provides five network diagnostic tools. These commands can be executed directly within the web interface with the stdout presented on screen.

Diagnostic tools are located in Node > Diagnostics and are as follows:

  • Ping
  • TCP Connect
  • NSLOOKUP
  • TRACEROUTE
  • TCPDUMP
  • IOSTAT

Ping

Use this to 'ping' or test the network connection. Enter a known target host IP address that you wish to test into the Host field. Select Test and the stdout should resemble the example below.

If there is a network connection issue, the result will look more like the example below.

If this is the result, ensure that the target device is available and online, and that you have connected your appliance to the network correctly.

Please note that ping only confirms that the specified device is reachable by the appliance, it does not guarantee a connection to the specified device.

TCP Connect

Use this tool to establish a successful connection from GEM to another host via TCP for data exchange.

Enter the target host IP address and port in the Host and Port fields respectively.

Select Test.

The output should report Connected successfully. If it does not, check that the target port is open and available across the network from your GEM appliance.

NSLOOKUP

Use this tool to query the DNS (Domain Name Server) from GEM to obtain a DNS name from an IP address.

Enter the domain name you wish to resolve in the Domain Name field and select Test.

The resultant output should include both the IP address and domain name.

TRACEROUTE

Use this tool to determine the path that a packet takes from the appliance to another device.

Enter the target host IP address in the HOST field and select Test. Output of the result will be shown in the window.

Results may include a long list of servers across which the request traveled, together with latency statistics. This can aid in diagnosing latency or networking issues.

TCPDUMP

Use this to capture TCP packets that have been received over a network on a specific interface.

Specify the network interface you wish to use in the Network Interface and Host fields.

Enter the destination port of the local host in the Port field.

Note: Specifying the Port and Host are optional for the TCPDUMP command.

IOSTAT

Use IOSTAT to monitor system input/output. Specify the storage device under Device, and the number under Interval and Count.