Troubleshooting
Problem
All routers are configured to send network traffic to QRadar, but seeing a fraction of expected flows in Network Activity.
Symptom
A good sign there are missing flows, is that the system is nowhere near the licensed Flow capacity and all flows are configured.
- From the web UI Console, go to Admin > System and License Management.
- View the Flow Rate Limit, and make a note of it.
NOTE: The first number is the license limit per minute and the second number is the hardware limit. - Go to Network Activity.
- Process a one minute search.
- Expand Current Statistics.
- The Total Results is your current rate.
- If the value from step 6 is less than 30% of the value from step 2, then your flows might not be configured correctly.
Cause
Flows might not be near the license for other reasons, aside from misconfiguration:
- A router might not be set up to forward the flows correctly
- A firewall might be blocking or dropping the network packets
- A duplicate port might be in use, preventing the proper sending or receiving of the packets
- One or more servers were decommissioned and are no longer send flows
There are many other reasons not listed that could also explain missing flows.
Resolving The Problem
Create a list of network devices that are sending into QRadar but need configuration:
NOTE: Some flows are not captured from this method.
NOTE: Replace file_name
and file_name_2
with titles that make sense and are referenceable to your team.
-
tcpdump icmp | grep "udp port sflow unreachable" | awk '{print $5}' > file_name
- Wait 2 minutes then,
Ctrl+C
on your keyboard to end the command.
NOTE: First, try the tcpdump command for 2 minutes. Then, 5 minutes, if you don't get anything. Then, up to 20 minutes for a larger list. The approach is because some systems are getting millions of flows while others are getting thousands of flows and you don't want to fill up disk space. -
sort file_name > file_name_2
-
uniq file_name_2
- The resulting output is a list of all Flows that do not have correct, or existing, Flow configuration.
- After the flows are configured, from the link provided in step 5, you will see increased activity in Network Activity for new events.
Related Information
Document Location
Worldwide
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Document Information
Modified date:
25 August 2022
UID
ibm16586970