Diagnosing network problems

About diagnosing network problems

The netdiag command automatically and easily diagnoses network problems.

This command analyzes the statistics continuously gathered by Data ONTAP and performs diagnostic tests to identify and report problems related to the physical, network, or transport layers. If any problems are found, the command output also suggests remedial actions.

Syntax of the netdiag command

The netdiag command syntax is as follows:

netdiag [-s|v|d] [-nbat] [-p [-I interface]]

For information about all the options available with the netdiag command, see the na_netdiag(1) man page.

Diagnosing transport layer problems

To diagnose transport layer problems in your filer, complete the following step.

Step	Action
1	Enter the following command: netdiag -t Example: A filer whose TCP window size is smaller than the recommended value displays the following output when the above command is run: Performing transport layer diagnostics..... The TCP receive window advertised by CIFS client 10.10.10.10 is 8760. This is less than the recommended value of 32768 bytes. You should increase the TCP receive buffer size for CIFS on the client. Press enter to continue.

Step

Action

Enter the following command:

netdiag -t

Example:

A filer whose TCP window size is smaller than the recommended value displays the following output when the above command is run:

Performing transport layer diagnostics.....

The TCP receive window advertised by CIFS client 
10.10.10.10 is 8760. This is less than the recommended 
value of 32768 bytes. You should increase the TCP receive 
buffer size for CIFS on the client. Press enter to 
continue.