Fortianalyzer log forwarding for incremental logs

[Naved]

Hi,

We are using FortiAnalyzer version 7.0.8, wherein logs are being forwarded to a syslog server for traffic learnt from Fortigate firewalls. Amount of logs being forwarded are quite huge per minute as seen from forward traffic logs learnt on Fortigate firewall (source FortiAnalyzer to destination Syslog server).

Log rate seen on the FortiAnalyzer is approximately 500.

Can we have only incremental logs being sent from FortiAnalyzer to the syslog server.

Thanks,

Naved.

[AEK]

Hello

What is meant by incremental logs?

[Naved]

Hi @AEK 

In the traffic logs I can see that the amount of sent bytes from FortiAnalyzer to syslog is 37GB every 2 to 3 minutes and increasing.

Logging is enabled as Realtime on FortiAnalyzer for sending logs to syslog.

I think the way firewall presents this is not appropriate, because i still see that FortiAnalyzer is sending almost around 37 GB of Sent Bytes every 2 to 3 minutes. But upon checking with the syslog team they confirmed that the size of logs received are only around 3 MB per minute.

Appreciate if you could explain this behavior and if it has any impact on performance.

Thanks.

[AEK]

Hi Naved

Could you please share a screenshot showing sent bytes?

[Naved]

Hi @AEK ,

Please find below FYR.

@AEK FYR

Thanks.

[Debbie_FTNT · Accepted solution]

Dear Naved,

this may be a simple misunderstanding of the log:
- FortiGate generates logs for ongoing sessions every two minutes

- this log contains two sets of sent/received information: the total for the session, and the delta since the last log for the same traffic session

-> if the traffic session has been going on for some time (check the 'duration' field in log message), then the total can add up a lot; the 'delta' values would tell you how much was sent since the last log, so within the last two minutes