Not able to discover a device (Legacy KB ID CNC TS12896 )

Document ID : KB000052421
Last Modified Date : 14/02/2018
Show Technical Document Details
This is normally due to a highly utilized network or service running on a device.


From the $NH_HOME/bin directory enter the command:


        nhDiscover -c <community string> -t 60 -ret 3 -o outfile.txt -res results.txt <IP address>


where <community string> is the community string and <IP address> is the IP address of the element in question. Check the output files (outfile.txt and results.txt) for success in the discovery. If the device was found, reduce the timeout value, specified by the -t argument, by half and repeat the test until the value is no longer successful. Use the lowest successful value for the NH_DISCOVER_TIMEOUT environmental variable.  NH_DISCOVER_RETRIES (-ret in the command line) can also be tested if a timeout value usually works, but not always.  Increasing the retry count can help in this situation.


The NH_DISCOVER_TIMEOUT and NH_DISCOVER_RETRIES variables are added to the nethealthrc.sh.usr file on a UNIX system or modified in the System control panel applet on an NT system.  In eHealth 6.1, discover policies can be adjusted to take these into account as well.


If the issue persists with high timeout values, try setting the following environment variable and rediscovering the device 

NH_DISCOVER_IGNORE_ERROR=ON

This will allow the discovery process to move on when the error is received and discover what it can based on what is available in the MIB of the device.

This environment variable is set to off by default. If it has not been defined previously, it may not appear as a current environment variable (so you will have to add it).

For more information on how to set environment variables, click on the appropriate link below:

How to Set or Change eHealth Environment Variables-Unix

How to Set or Change eHealth Environment Variables-NT

.

Related Issues/Questions:
Not able to discover a device
Discovery fails with error: "<IPaddress> (community string) Received SNMP error noResponse"
Discovery does not find all elements
How to use the NH_DISCOVER_IGNORE_ERROR environment variable
Not all expected elements are discovered on a device
Only some of the elements on a device are found

Problem Environment:
Discover
eHealth
 The device responds to ping from the eHealth server and provides SNMP output using the nhSnmpTool command: nhSnmpTool -c <community string> -i -n <IP address>

Causes of this problem:
The finder process stopped received responses form the device or received a malformed response from the device during discovery

Additional Information:



(Legacy KB ID CNC TS12896 )