Configure SNMP on ESXi

Login into VMware host using SSH and root credentials, then set community string that you are going to use, and enable SNMP service. 

esxcli system snmp set --communities YOUR_COMMUNITY_STRING
esxcli system snmp set --enable true

Replace YOUR_COMMUNITY_STRING with the Community string you are going to use, usually this is Private or Public but I think you need to use some unique string one for security reasons. Enable SNMP on ESXi firewall

Now we need to add a firewall rule to allow inbound SNMP traffic to our ESXi host. For this, we have two options:

1.Allow all traffic for SNMP
2.Allow traffic from specific hosts or subnets

Allow traffic from All hosts

esxcli network firewall ruleset set --ruleset-id snmp --allowed-all true
esxcli network firewall ruleset set --ruleset-id snmp --enabled true

Allow traffic from specific hosts or subnets

esxcli network firewall ruleset set --ruleset-id snmp --allowed-all false
esxcli network firewall ruleset allowedip add --ruleset-id snmp --ip-address 192.168.1.0/24
esxcli network firewall ruleset set --ruleset-id snmp --enabled true

Restart SNMP Service

Now that we have done our VMware 6.5 SNMP configuration we need to restart the SNMP service 

/etc/init.d/snmpd restart
esxcli system snmp set --communities public
esxcli system snmp set --enable true
esxcli network firewall ruleset set --ruleset-id snmp --allowed-all false
esxcli network firewall ruleset allowedip add --ruleset-id snmp --ip-address 10.0.2.0/24
esxcli network firewall ruleset set --ruleset-id snmp --enabled true
/etc/init.d/snmpd restart