SNMP traps are not received by monitoring server when alarms in vCenter are triggered

Products

• VMware vCenter Server
• VMware vCenter Server 7.0
• VMware vCenter Server 6.0

Issue/Introduction

• Alarms configured to send SNMP traps do not send traps when triggered.
• No SNMP traps are received by monitoring server (can be seen with TCPDUMP).
• Using "snmp.test" command from VCSA command-line sends a trap that is captured by TCPDUMP.

Cause

This issue occurs due to 2 separate agents on the vCenter Appliance - one for vpxd and one for snmp. Alarms use the vpxd agent to send traps whereas the snmp agent allows for traps to be sent to servers outside of the VCSA.

Resolution

VMware is aware of this issue however currently there is no resolution. 

 

To workaround this issue, follow the below steps, ensure you have a valid backup before proceeding:

-Download the RPM attached to this KB article and upload it to the vCenter Appliance using WinScp. Please see the following KB https://knowledge.broadcom.com/external/article?articleNumber=326317 if there are issues connecting to the Appliance with WinScp.

-Run the following command to install the RPM:
rpm -ivh vmware-spp-1.1.0-Linux.rpm

-Ensure that the the service vmwspp is installed:
ls /etc/systemd/system | grep vmwspp

-In the vCenter GUI, ensure that vpxd SNMP configuration is the same as below. The configuration is found under vCenter -> Configure -> SNMP receivers.


-Setup the VCSA SNMP agent to send SNMPv3 traps as per the following documentation:
https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.vcsa.doc/GUID-3695CE84-C6DF-497E-BA4E-2B341CC366C5.html 

-Ensure that the vmwspp service is running and listening on 127.0.0.1 port 162:
netstat -nap | grep vmwspp

If it is not, stop and start the service and check once more:
systemctl stop vmwspp
systemctl start vmwspp