Command>snmp.set --v3targets hostname@port/user-id/secLevel/trap
/var/log/vmware/applmgmt/applmgmt.log
yyyy-mm-ddThh:mm:ss.Z DEBUG:vmware.vherd.transport.xmlrpc:Dictionary returned: {'code': 'com.vmware.applmgmt.err_snmp_badv3_target', 'message': 'The SNMP v3 target format is invalid. The format to use is: ip-or-hostname[@port]/remote-user/security-level trap|inform[,...].', 'attributes': {}, '__error__': True}
VMware vCenter Server 7.x
The SNMP user id format is invalid, user id should only consist of alphanumeric characters (uppercase letters, lowercase letters, and numbers).
To resolve this issue, specify a valid user name only consisting of a combination of alphanumeric characters : uppercase letters, lowercase letters, and numbers.
Below command is a sample for reference only:
For other details please refer to https://knowledge.broadcom.com/external/article/382878/how-to-configure-snmpv3-on-the-vcenter.html