Troubleshooting for SNMP Trap Receiver for NetIM
Description
This KBA is applicable when the SNMP Trap Receiver has been configured as per the user guide.
Solution
Follow the below steps to validate the configuration on devices:
1. For Cisco devices, validate the SNMP Trap configuration with the below commands:
a. SNMP v3 Trap example:
i. snmp-server host <NetIM Core IP> traps version 3 priv <SNMP User>
b. SNMP v2c Trap example:
i. snmp-server host <NetIM Core IP> traps version 2c <SNMP Community string>
c. Make sure SNMP Traps are enabled with the below command:
i. For all types of trap
1) snmp-server enable traps
ii. For selective traps:
1) snmp-server enable traps config
2) snmp-server enable traps syslog
3) snmp-server enable traps snmp
4) snmp-server enable traps link
d. Validate SNMP User, Group, & host configuration:
i. show snmp user
ii. show snmp group
iii. show snmp host --> Confirm the IP Address of NetIM Core
iv. show running-config | section snmp
2. On NetIM, validate the SNMP Trap Receiver configuration.
3. Confirm if the default SNMP Trap Port 8162 is allowed in the firewall through the following command on the NetIM Core bash:
a. Firewall show
b. NOTE: If the SNMP Trap Receiver port is changed, then the port should be allowed in the firewall rule as well as in the network. Additionally, map the custom port to the default port on the core.
i. Follow the KBA to map the port: https://supportkb.riverbed.com/support/index?page=content&id=S33800
Steps to confirm the SNMP Trap connectivity:
If all the above mentioned steps are performed and still the issue persists, then follow the below steps to confirm the issue is somewhere in the network:
1. Send a sample trap through the below Cisco Command:
a. snmp test trap linkdown
b. snmp test trap linkup
2. Capture the packets on the NetIM core bash through the tcpdump commands as below:
a. #sudo tcpdump -i ens192 host <Network Device> and port <SNMP Trap Port>
Root Cause:
• If there are no packets on the NetIM core, it indicates that the SNMP Traps are not being forwarded to the NetIM Core.
○ In such a case, check if there is any firewall restriction in the network.
○ Validate if the NetIM Core IP is configured for SNMP.
NOTE:
• ACLs do NOT control traps the same way they control SNMP polling.
• ACLs are applied either:
○ To SNMP polling access (UDP 161), or
○ On the interface/firewall path for trap traffic (UDP 162)
Related Files
Environment
NetIM 2.X.X
NOTICE: Riverbed® product names have changed. Please refer to the Product List for a complete list of product names.
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