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Flow source x.x.x.x is not responding! Please check whether it is working properly.

Updated: 

 

Information

 

Summary:

Flowmon appliance receives the following warning: "Flow source x.x.x.x is not responding! Please check whether it is working properly."
Environment:

Product: Flowmon OS

Version: Any

Platform: Any
Question/Problem Description:

One of the issues this can be caused by is that SNMP requests timeout is 250ms, which is the default live check timeout and SNMP info update timeout - resulting in these warnings
Steps to Reproduce:  
Error Message:

Flow source x.x.x.x is not responding! Please check whether it is working properly.
Defect Number:  
Enhancement Number:  
Cause: The flow source is not responding fast enough to SNMP requests.
Resolution:

User can increase the timeout values in "Configuration Center - FMC Configuration - Sources". Increasing it to 500ms on both timeouts should be generally enough.

Measure the response time in CLI with the following command:

time snmpbulkwalk -Cr20 -v 2c -c "<community_string>" -r 1 -t 10 <flow_source_IP> sysDescr

Adjust the timeout according to the measured value.
Workaround:  
Notes:  
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Comments

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Adam Caha

Hello, 

 

is there any technical, or "meaningful" timeout limit? 0,5s is not enough for all of our sources....

Thanks for confirmation

Regards

Adam

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Jakub Konecny

Hello,

The limit is meaningful, especially for many flow sources.

Flow source live check if performed every 300 seconds. It is requesting one OID:
1.3.6.1.2.1.1.1 - sysDescr
and there is one retry. Flow sources are queried one by one. So in case of flow source unavailability, it takes 500 ms (2x250 ms) to finish the query. If there are 1000 flow sources it might take 500 seconds in the worst case. So the system won't be able to query all flow sources every 300 seconds as expected.

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Jan Chury

Hello,
in System messages in WebUI we can find the message that flow source stopped responding as well as a message that flow source started responding again when the probe is back on-line.

But in syslog there is just "not responding" message however we can't find message "Flow source xxx.xxx.xxx.xxx started responding." there.

Is it possible to enable it in syslog somewhere?


Best regards

Jan Chury

0
Avatar

Jakub Konecny

Hello Jan,

It is currently not possible to enable this message in the Configuration Center. The message that the flow source started responding has low severity; thus, it is not sent to the syslog server. 

I have already reported your comment to our product management team, and we might change the behavior in the future to send this message to syslog/SNMP/mail even if it is low severity. 

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